pack and unpack were added to the table library recently by around 6 days ago, however they do not have documentation put up (not even the notion that they exist) and they aren’t visible in Studio intellisense.
Not sure if this has already been scheduled for a write or they actually weren’t documented.
table.pack and table.unpack are live and working right now, however they are still not listed in the table library documentation and do not show up in Studio intellisense (should I be filing a Studio bug report for that since IX doesn’t handle Studio?).
Housekeeping: this is resolved in the Creator Documentation (and also highlights in intellisense as both posts above had highlighted that not being the case).