At the restaurant that I used to work, we used to have a couple come every other Friday about 8ish with their very young children. Children used to eat first (small snack)while adults socialise with a bottle of wine. Children taken through to the loos (nice ones). Changed into pj's, teeth cleaned, taken back to table popped into their sleeping bags to sleep UNDER the tables. Then the adults used to eat and have fun. Not what I would do myself for my family, but it worked for them and the children were never any bother. More importantly they enjoyed it.
However I have been on both sides of the fence. 3 of my children were fine. The 4th suffers from ADHD and even though he is 11 now, I pick where I eat out (very rare occasions) carefully because he would find it hard to cope. He DOESN'T want to always eat at McDonald's. Only had one nightmare, when I paid up and left half way through a meal.
Some of the nicest and politest people that I have served in a restaurant, were those that had physical and mental disabilities.