The earlier you get there for breakfast the better. It tends to get crowded as you get nearer the parks opening times. Or you can wait until everyone leaves for the parks.
As far as dinner goes, like most CS it's best if you eat dinner either early, or late. As the parks close for the day, the food court will definitely get more crowded. Depending on when you are going and when the parks close, you can use that as your guide.