You preceded that by saying, "namely, that [my] choices are let the kid do what he or she wants or let him or her have a tantrum."
I believe your interpretation was mistaken. These are not two choices. Rather, they are virtually one in the same. The 3 y.o. wants to throw a tantrum. They want to go table to table, bothering other patrons. Many times, others brush the first occurrence off and maybe a second time, but get increasingly annoyed with frequency. The distraction, whatever it may be, is a tool in preventing that.