I think it may depend on the time of year. I know they were taking reservations until at least 9 PM on July 4th weekend. If you call the hotel directly, they will be able to tell you. I know the restaurants on CW are opened later. Sunday night after July 4th we ate at Trattoria del Porto at 7 PM and it was empty. Earlier in our stay, it was much, much busier. The night we were there they had a $20 buffet which included a non-alcoholic drink and a dessert bar. It was not the best buffet but it served it's purpose and was economical. DS ordered the spaghetti instead of the buffet which is what we will order next time. It was really very tasty. Yum!
Mama's is several calibers above Trattoria and you will love it! Reservations are recommended so keep that in mind. You should be able to make them when you arrive. It is not like WDW where you have to make a reservation 180 in advance.