How is it that much of what ksandness and I said above was useless?

OP's question was, can they bring in outside food for their 21mo child. We suggested no. I don't disagree with anything in your post which I'm sure will be of value to the OP, and I too said that little kids are welcome at most restaurants in general in #4. But we were more directly addressing the OP's question as to bringing outside food into restaurants.