If you mean Cinderella's Royal Table in the castle then yes you absolutely nedd a ressie, and it is the single most sought after ressie at WDW. If you are not on the phone or online at exactly 6:00 on your ADR day odds are slim to none that you can get it. Even then there is no guarantee. I have been told that breakfast fills in a matter of a few minutes, and it is a little easier to get lunch or dinner than breakfast. We did the lunch last year, and we really enjoyed it. There was something magical about just being in the castle.The food was not that special, and certianly not worth the price, buty ou are really paying for the atmosphere, and the interaction with the princesses. I am glad we did it, but i think once is fine for us.