Table of safe spots to spawn taking too long to generate and being unable to accuratley wait

Hi! I have my code generating a table of safe spots for the mob to spawn, and then it will pick a random number and see if its in the table, if its not just rerun the random pick until it is, simple enough right?
The table is taking too long to generate so I then cant get it to pick a random from the full table

End table:

table: 0xe064f13e307bdd01 = {
                    ["1, 1"] = true,
                    ["1, 10"] = false,
                    ["1, 11"] = false,
                    ["1, 12"] = true,
                    ["1, 13"] = true,
                    ["1, 14"] = true,
                    ["1, 15"] = true,
                    ["1, 16"] = true,
                    ["1, 17"] = true,
                    ["1, 18"] = true,
                    ["1, 2"] = false,
                    ["1, 3"] = false,
                    ["1, 4"] = false,
                    ["1, 5"] = false,
                    ["1, 6"] = false,
                    ["1, 7"] = false,
                    ["1, 8"] = false,
                    ["1, 9"] = false,
                    ["10, 1"] = false,
                    ["10, 10"] = true,
                    ["10, 11"] = true,
                    ["10, 12"] = false,
                    ["10, 13"] = true,
                    ["10, 14"] = true,
                    ["10, 15"] = true,
                    ["10, 16"] = true,
                    ["10, 17"] = false,
                    ["10, 18"] = false,
                    ["10, 2"] = false,
                    ["10, 3"] = false,
                    ["10, 4"] = false,
                    ["10, 5"] = false,
                    ["10, 6"] = false,
                    ["10, 7"] = false,
                    ["10, 8"] = false,
                    ["10, 9"] = false,
                    ["11, 1"] = false,
                    ["11, 10"] = true,
                    ["11, 11"] = true,
                    ["11, 12"] = false,
                    ["11, 13"] = true,
                    ["11, 14"] = true,
                    ["11, 15"] = true,
                    ["11, 16"] = true,
                    ["11, 17"] = false,
                    ["11, 18"] = false,
                    ["11, 2"] = false,
                    ["11, 3"] = true,
                    ["11, 4"] = true,
                    ["11, 5"] = true,
                    ["11, 6"] = true,
                    ["11, 7"] = true,
                    ["11, 8"] = true,
                    ["11, 9"] = false,
                    ["12, 1"] = false,
                    ["12, 10"] = true,
                    ["12, 11"] = true,
                    ["12, 12"] = false,
                    ["12, 13"] = true,
                    ["12, 14"] = true,
                    ["12, 15"] = true,
                    ["12, 16"] = true,
                    ["12, 17"] = false,
                    ["12, 18"] = false,
                    ["12, 2"] = false,
                    ["12, 3"] = true,
                    ["12, 4"] = true,
                    ["12, 5"] = true,
                    ["12, 6"] = true,
                    ["12, 7"] = true,
                    ["12, 8"] = true,
                    ["12, 9"] = false,
                    ["13, 1"] = false,
                    ["13, 10"] = true,
                    ["13, 11"] = true,
                    ["13, 12"] = false,
                    ["13, 13"] = true,
                    ["13, 14"] = true,
                    ["13, 15"] = true,
                    ["13, 16"] = true,
                    ["13, 17"] = false,
                    ["13, 18"] = false,
                    ["13, 2"] = false,
                    ["13, 3"] = true,
                    ["13, 4"] = true,
                    ["13, 5"] = true,
                    ["13, 6"] = true,
                    ["13, 7"] = true,
                    ["13, 8"] = true,
                    ["13, 9"] = false,
                    ["14, 1"] = false,
                    ["14, 10"] = true,
                    ["14, 11"] = true,
                    ["14, 12"] = false,
                    ["14, 13"] = false,
                    ["14, 14"] = false,
                    ["14, 15"] = false,
                    ["14, 16"] = true,
                    ["14, 17"] = false,
                    ["14, 18"] = false,
                    ["14, 2"] = false,
                    ["14, 3"] = true,
                    ["14, 4"] = true,
                    ["14, 5"] = true,
                    ["14, 6"] = true,
                    ["14, 7"] = true,
                    ["14, 8"] = true,
                    ["14, 9"] = false,
                    ["15, 1"] = false,
                    ["15, 10"] = true,
                    ["15, 11"] = true,
                    ["15, 12"] = true,
                    ["15, 13"] = true,
                    ["15, 14"] = true,
                    ["15, 15"] = true,
                    ["15, 16"] = false,
                    ["15, 17"] = false,
                    ["15, 18"] = false,
                    ["15, 2"] = false,
                    ["15, 3"] = true,
                    ["15, 4"] = true,
                    ["15, 5"] = true,
                    ["15, 6"] = true,
                    ["15, 7"] = true,
                    ["15, 8"] = true,
                    ["15, 9"] = false,
                    ["16, 1"] = false,
                    ["16, 10"] = true,
                    ["16, 11"] = true,
                    ["16, 12"] = true,
                    ["16, 13"] = true,
                    ["16, 14"] = true,
                    ["16, 15"] = true,
                    ["16, 16"] = true,
                    ["16, 17"] = true,
                    ["16, 18"] = true,
                    ["16, 2"] = false,
                    ["16, 3"] = false,
                    ["16, 4"] = false,
                    ["16, 5"] = false,
                    ["16, 6"] = false,
                    ["16, 7"] = true,
                    ["16, 8"] = false,
                    ["16, 9"] = false,
                    ["17, 1"] = false,
                    ["17, 10"] = true,
                    ["17, 11"] = true,
                    ["17, 12"] = true,
                    ["17, 13"] = true,
                    ["17, 14"] = true,
                    ["17, 15"] = true,
                    ["17, 16"] = true,
                    ["17, 17"] = true,
                    ["17, 18"] = true,
                    ["17, 2"] = false,
                    ["17, 3"] = false,
                    ["17, 4"] = false,
                    ["17, 5"] = false,
                    ["17, 6"] = false,
                    ["17, 7"] = false,
                    ["17, 8"] = true,
                    ["17, 9"] = true,
                    ["18, 1"] = true,
                    ["18, 10"] = true,
                    ["18, 11"] = true,
                    ["18, 12"] = true,
                    ["18, 13"] = true,
                    ["18, 14"] = true,
                    ["18, 15"] = true,
                    ["18, 16"] = true,
                    ["18, 17"] = true,
                    ["18, 18"] = true,
                    ["18, 2"] = false,
                    ["18, 3"] = false,
                    ["18, 4"] = true,
                    ["18, 5"] = true,
                    ["18, 6"] = true,
                    ["18, 7"] = true,
                    ["18, 8"] = true,
                    ["18, 9"] = true,
                    ["2, 1"] = false,
                    ["2, 10"] = false,
                    ["2, 11"] = false,
                    ["2, 12"] = false,
                    ["2, 13"] = false,
                    ["2, 14"] = false,
                    ["2, 15"] = false,
                    ["2, 16"] = true,
                    ["2, 17"] = false,
                    ["2, 18"] = false,
                    ["2, 2"] = true,
                    ["2, 3"] = false,
                    ["2, 4"] = false,
                    ["2, 5"] = false,
                    ["2, 6"] = false,
                    ["2, 7"] = false,
                    ["2, 8"] = false,
                    ["2, 9"] = false,
                    ["3, 1"] = false,
                    ["3, 10"] = false,
                    ["3, 11"] = false,
                    ["3, 12"] = false,
                    ["3, 13"] = true,
                    ["3, 14"] = false,
                    ["3, 15"] = false,
                    ["3, 16"] = false,
                    ["3, 17"] = false,
                    ["3, 18"] = false,
                    ["3, 2"] = true,
                    ["3, 3"] = true,
                    ["3, 4"] = true,
                    ["3, 5"] = true,
                    ["3, 6"] = true,
                    ["3, 7"] = true,
                    ["3, 8"] = false,
                    ["3, 9"] = false,
                    ["4, 1"] = false,
                    ["4, 10"] = true,
                    ["4, 11"] = true,
                    ["4, 12"] = true,
                    ["4, 13"] = true,
                    ["4, 14"] = false,
                    ["4, 15"] = false,
                    ["4, 16"] = false,
                    ["4, 17"] = true,
                    ["4, 18"] = false,
                    ["4, 2"] = true,
                    ["4, 3"] = true,
                    ["4, 4"] = true,
                    ["4, 5"] = true,
                    ["4, 6"] = true,
                    ["4, 7"] = true,
                    ["4, 8"] = false,
                    ["4, 9"] = false,
                    ["5, 1"] = false,
                    ["5, 10"] = true,
                    ["5, 11"] = true,
                    ["5, 12"] = true,
                    ["5, 13"] = false,
                    ["5, 14"] = false,
                    ["5, 15"] = false,
                    ["5, 16"] = false,
                    ["5, 17"] = true,
                    ["5, 18"] = false,
                    ["5, 2"] = true,
                    ["5, 3"] = true,
                    ["5, 4"] = true,
                    ["5, 5"] = true,
                    ["5, 6"] = true,
                    ["5, 7"] = true,
                    ["5, 8"] = false,
                    ["5, 9"] = false,
                    ["6, 1"] = false,
                    ["6, 10"] = true,
                    ["6, 11"] = true,
                    ["6, 12"] = false,
                    ["6, 13"] = false,
                    ["6, 14"] = false,
                    ["6, 15"] = false,
                    ["6, 16"] = false,
                    ["6, 17"] = false,
                    ["6, 18"] = false,
                    ["6, 2"] = true,
                    ["6, 3"] = true,
                    ["6, 4"] = true,
                    ["6, 5"] = true,
                    ["6, 6"] = true,
                    ["6, 7"] = true,
                    ["6, 8"] = false,
                    ["6, 9"] = false,
                    ["7, 1"] = false,
                    ["7, 10"] = true,
                    ["7, 11"] = true,
                    ["7, 12"] = false,
                    ["7, 13"] = false,
                    ["7, 14"] = false,
                    ["7, 15"] = false,
                    ["7, 16"] = false,
                    ["7, 17"] = false,
                    ["7, 18"] = false,
                    ["7, 2"] = false,
                    ["7, 3"] = false,
                    ["7, 4"] = false,
                    ["7, 5"] = true,
                    ["7, 6"] = false,
                    ["7, 7"] = false,
                    ["7, 8"] = false,
                    ["7, 9"] = false,
                    ["8, 1"] = true,
                    ["8, 10"] = true,
                    ["8, 11"] = true,
                    ["8, 12"] = false,
                    ["8, 13"] = true,
                    ["8, 14"] = true,
                    ["8, 15"] = true,
                    ["8, 16"] = true,
                    ["8, 17"] = false,
                    ["8, 18"] = false,
                    ["8, 2"] = true,
                    ["8, 3"] = false,
                    ["8, 4"] = false,
                    ["8, 5"] = false,
                    ["8, 6"] = true,
                    ["8, 7"] = true,
                    ["8, 8"] = false,
                    ["8, 9"] = false,
                    ["9, 1"] = false,
                    ["9, 10"] = true,
                    ["9, 11"] = true,
                    ["9, 12"] = false,
                    ["9, 13"] = true,
                    ["9, 14"] = true,
                    ["9, 15"] = true,
                    ["9, 16"] = true,
                    ["9, 17"] = false,
                    ["9, 18"] = false,
                    ["9, 2"] = false,
                    ["9, 3"] = false,
                    ["9, 4"] = false,
                    ["9, 5"] = false,
                    ["9, 6"] = false,
                    ["9, 7"] = false,
                    ["9, 8"] = false,
                    ["9, 9"] = true
                 }  -  Server - mazetester:18

Code that adds values to the table:

elseif v:IsA("Model") and v:FindFirstChild("central") then
	local childs = v:GetChildren()
	--print(v.Name.. " ; ".. tostring(#childs))
					
	if #childs > 2 then
		safeToSpawn[v.Name] = false
	elseif #childs <= 2 then
		safeToSpawn[v.Name] = true
	end
	spawnMob()
end

and the spawnmob() function had a variable to tell it that once its fired it cant fire again, but then it fires on 1,1 always and cant get the full table, im not sure what to do here

Is there a way that I can make a table wait to have X amount of values in it or something of the sorts?

Could you just not insert spots that aren’t safe to spawn at? It just seems really redundant since they aren’t useful and is cluttering up the table
Fill the table with only safe spots and perhaps use a different format so that the table is an array and therefore easier to pick a random value from

Perhaps a format like:

{
  {1, 1},
  {1, 2},
  {1, 3},
  {1, 4}, --and so on
}

And to pick a random spot you just index a random number that’s in the range of the number of indices

local randomSpot = safeToSpawn[math.random(#safeToSpawn)]

The spots are randomly generated so I dont know which spots will be safe or not, so no I cant