If you want to eat a lot in Prague, Amibiente Brasileiro might be a good option for you. In this restaurant you can pay to eat as much as you want from a salad buffee, or you can pay to eat unlimited from the salad buffee and a beef buffee (Churrasco rodizio). If you want more after this you can go for the dessert, but that is not included in the menu price.
Ambiente Brasileiro is located in the center of Prague, not far from the Old Town Square. You have two restaurants to choose between, the addresses can be found below:
Ambiente Braileiro Prague
U Radnice 8/13, 110 00 Praha 1 (near Old Town Square)
Na Příkopě 22, 110 00 Praha 1
Ambiente Brasileiro pictures