Hi Michelle:
The Grand Gathering Breakfast at Tony's Town Square is a wonderful way to enjoy breakfast with a large party. Any little ones in your group will have a great meal with Mickey and his friends, and we find the characters at the Grand Gathering Breakfast to be among the more interactive of the character dining options.
The Grand Gathering Breakfast is held at Tony's Town Square, which is located right on Main Street, U.S.A. Check the map
here, click "View Map," scroll down, and click Tony's Town Square for a close-up view of the location on the map. It sounds like you are thinking of a different section of the Magic Kingdom called Mickey's Toontown Fair, which is a fun section in the park for little ones to play.
Enjoy your Grand Gathering Disney vacation.