Congratulations on getting a PS for CRT! You will have a wonderful time. I've had the pleasure of having breakfast at the castle and I have never felt rushed while eating/seated at our table. Hey, you're paying for it - so relax and enjoy your time in the castle. It is a beautiful building (make sure you check out all the small details). The earliest seating is 8:10 a.m. - my favorite time. I believe the last PS is for 10:30 or 10:45. Our last visit was in November and IMHO the food was very good. I loved the fresh fruit with the yogurt topping - yummy. It was waiting for us on the table with a big basket of breakfast rolls, muffins, etc. Please remember that you can ask for seconds on any of the items that they serve.
I can't remember the number of people that they seat at once (I think it's about 120 people?) - it's a pretty small dining room. Maybe someone else will have that answer. Enjoy your breakfast!