Hello, Richard!
Welcome to planDisney. I am glad you sent us your question! We celebrated my youngest child's birthday at
Cinderella's Royal Table, who was smiling and laughing the entire time. It made my heart so happy!
You are correct that the areas surrounding Cinderella Castle can be busy when a Nighttime Spectacular fireworks performance is about to begin. I just checked the
Walt Disney World Resort Entertainment Schedule, and
Happily Ever After is currently scheduled to begin at 9:20 P.M. during the week of your visit. If you do not want to watch Happily Ever After, you should not have any issues getting to your 9:00 P.M. dining reservation. Guests can usually
check in for their dining reservations up to 10-15 minutes in advance on the My Disney Experience app. I recommend walking through Fantasyland to arrive at the check-in desk for Cinderella's Royal Table, and if the area is blocked off for some reason, just let a nearby Cast Member know that you are arriving for your dinner reservation. Schedules are subject to change, so make sure to check the app as it gets closer to your arrival date.
Some of my favorite attractions in Magic Kingdom Park are even better at nighttime! My favorite attractions to experience in the evening are
Big Thunder Mountain Railroad,
Seven Dwarfs Mine Train, and
TRON Lightcycle/Run. I hope you get the chance to ride some of them before your dinner!
Richard, enjoy your elegant meal at Cinderella's Royal Table! We hope to see you real soon!
Wishing you a Happily Ever After!
Jen