Also not sure about the question.
On the regular dining plan there are sit-down (table service) credits and quick service (counter service) credits. The two do not mix. While you might be able in some places to trade one table service credit for one quick service meal, you can never trade counter service credits for table service meals. Counter or quick service credits can be used only at counter service restaurants.
On the deluxe dining plan there are just meal credits. You can use these credits anywhere you want - they are good for either table service or counter service.