Going back to when I was a child, there were never any coloring books, etc. We were expected to sit quietly with the rest of the family and enjoy each other's company. We were so pleased to be out to a restaurant, which was a rare occsaion, so that we always behaved ourselves. If we had not, we would have been unceremoniously removed from the dining room.
I think that children should be exposed frequently to dining in a restaurant and their parents should explain the finer aspects of same. How else would they learn?