How would I know when a table is loaded since there is no WaitForChild function for tables?

so for example

table = {}

wait(4)

table[XD] = "MotherTruckerDudeThatHurtLikeAButCheekOnAStick"

since it waits 4 seconds I need to index it after 4 seconds right? but I need to use math.random so I cant always wait that time

is there any way I can use something similar to waitforchild to get table[XD]

I've thought of doing this

repeat wait() until table[XD] 

but this dont seem efficient lmao