Originally posted by Dave Beers:
They'll usually bring food out for the kids quickly too, and when our son was little it was common to see him happily eating his hot dog or pizza while we were still on the salad course.
That's been our experience, too. Of course, depending on how quickly or slowly he eats, it also means that he might be finished by the time your main course is served. What we did was to order an appetizer for him (carrot sticks/celery were always available), and that spaced his meal more closely to ours.
We also practiced at home by having longer meals in our own dining room starting a week or so before the cruise, and having a trial run in diners or other restaurants, so he'd know what to expect.