All Celebrity ships have a casual alternative dining option. There is a small charge ($2) per person and reservations are required. On the Century it is up in the Sky bar.
There is sushi available in the Islands cafe rear.
The two level dining room (The Grand Restaurant) is absolutely beautiful. You will be assigned to a table as well as a seating.
Order what ever you want, and if you don't like anything on the menu, there is always shrimp cocktail, steak, and chicken available.
The only charge is for soft drinks or alcohol.
Room service is available 24 hours a day.
The dining room is open seating for breakfast and lunch, and the islands cafe has a buffet during those times.
The grill is open by the pool for lunch as well as a specialty sandwich bar. In the morning the grill does omelets and eggs to order as well as fresh made belgian waffles.