Is this output showing what is sent to the new player before it is streamed in?
Yes, this is a breakdown of the data that cannot be loaded over time via streaming, the data that needs to be sent immediately on join.
WRT the lag, the first join that a server handles may take additional time, we cache some data between each join to reduce the workload, but the first join has no cache to work from. For severs handling live users this is typically not a problem (those servers normally handle many users over their lifetime, and by definition there is no user in the server before the first player joins to observe that high ping), but in studio most of the time when you test you are starting a new test server, so you “feel” that slowness each time.