If you don't care about the number of characters you see, going later is fine.
I think 11am is when they begin to wind-down breakfast.
The time we went at 10:30 we didn't have a problem getting enough food. There was plenty to select from.
But we had gone mainly for the character interaction. That time we only had a few come by our table.
It was real disappointing seeing the characters at distant tables expecting them to come by ours and then they slip into backstage room, to never re-appear.
Geemo