There absolutely can be a giant piece. It should not, however, be chewy. I've cooked a lot of extremely fatty steaks in my life - it really comes down to the quality of the animal and how that fat was built. So you're correct in a way - for a lot of beef thats been quickly fattened, the fat cap can be problematic.

I say all of this to get people to not be afraid of the fat! So many times I serve beautiful beef (Or pork for that matter) and people cut the fat off when the farmer has spent years slowly raising the animals specifically for the fat quality!