Hello Christie,
Welcome back to the Disney Parks Moms Panel!
Cinderella’s Royal Table is extremely popular, so I'm glad to hear you're already making your dining plans for your upcoming vacation.
I'm happy to report that Cinderella's Royal Table is a participating Character Dining experience on all the Disney Dining Plans except for Quick-Service Dining. For each person dining here, 2 table-service credits will be redeemed (and this includes gratuity). In terms of making your reservation, this is one restaurant that requires payment in full at the time you make your reservation. If you have a vacation package reserved that includes the Disney Dining Plan, I've heard it might be possible to avoid this advance payment. If it doesn't give you this option online, just call (407) WDW-DINE (939-3463) to inquire. Alternately, you can go ahead and make the payment at the time you book, and then get that refunded in full at the restaurant when you arrive for your reservation.
I hope that helps answer your question, Christie, but please let us know if we can help with anything else.
Wishing you pixie-dusted planning!
Beth