Yes there is. I think Plaza Gardens only serves a buffet.
Indeed this is where we ate one evening recently and there was no tea party going on.
I have to say we were just a little disappointed with Plaza Gardens. It looks so lovely from outside and I'm sure on a quiet day it's lovely inside too, but when we were there there were uncleared tables and dirty floors. Our waiter was really doing his best but seemed to have too much to do. The food was OK, no better, no worse. The good stuff was fresh fruit, bread, cheese, vegetables, desserts. The not so good was the nuggets, sausages, pizza, lasagne.
I suppose for the price [20 euros per person] for an all-you-can-eat buffet at the Magic Kingdom you can't expect too much. I wouldn't put anyone off going there, just be aware it's not 5 star.