It is set up in a portion of the buffet eating area that is not even visible to those using the buffet. We had our own waiter and virtually the same food as the dining room. We just stopped by an hour early and made a reservation. It was an easy way to get a good sit-down meal with waiter service after an excursion. Also a nice way to dine with new friends, other than your usual DR mates.
BTW, two n's in the word make it something related to a noisy 'din' (short i sound), not dine. Every time I read 'dinning' I have to smile and pronounce it as written.