I have taken my son to nice restaurants since he was little. When he did act up I would take him outside so I didn't bother anyone else. I use to tell my son in nice restaurants and in FC cabin. "Brandon, do you see any other kids here?" He would say no. I would say, "well kids are not suppose to be here but they are letting you come here but you must behave like an adult." Ok it was a fib but it worked
I recently went to a nice restaurant and 2 minutes after being sat a family was sat next to us with a LOUD baby and a LOUD 2-3 year old. I walked over to my server and said that I apoligize about this but I really was looking forward to a nice quiet dinner and would it be possible to be moved to another table. He said he understood and moved us across the room. I thanked him again. Dinner was great! The servers are very understanding. TRUST me when I say that servers are NOT happy when screaming kids are in the restaurant because it often cost them money but gratuities that they lose by nearby guests who have an unpleasant meal due to the commotion.