It is quite a lovely experience. I don't know why you made an ADR in the first place, but you and you child or other may really enjoy it. Why don't you read about it before cancelling. After all, how often do you get to eat i a castle? (And the Beauty & Beast dining is no comparison.) It is worth keeping, and a memory you will have for years.
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You said in your original post : " It's no special event or special dining that i'm aware of...just the usual i think?" If you really think Cinderella's Royal Table is no special event or special dining, maybe you should cancel. You may not enjoy it.