Random Numbers
1. Random(true) * Table.Count()
Random creates a random number between 0 and 1 and when set to "true" it updates with every doc edit. Multiplying by Table.Count() multiplies that number by the number of rows in a particular table, which bumps this random number over 1.
2.RoundUp(Random(true) * Table.Count())
RoundUp() just makes this a nice whole number to work with.
3.Table.Nth(RoundUp(Random(true) * Table.Count()))
This Table.Nth() formula takes the row number with the number being what's generated in step 2. You can see how in Step 3 the result is highlighted in blue as a row reference that you can hover on instead of just a number.