It seems to me there shouldn't be a limit on total quantity. If something runs out, it's the hotel's responsibility to replenish. That said, courtesy demands not emptying a selection with multiple portions, if others are waiting.

If there are 100 strips of bacon in the tray and you take 50, nobody but you and your cardiologist should care. But if there are 8 strips, and two people in line behind you, it's pretty rude to take all 8.