Hi Cathy,
As a Nana myself, I can assure you that visiting the Walt Disney World resort with your grandchildren is an unforgettable experience! If I had to choose between the
Coral Reef and
Akershus Royal Banquet Hall, I would likely select Akershus Banquet Hall. Actually, when children are involved, I nearly always lean toward Character Dining. It keeps them entertained, it makes for a super fun meal, and it reduces line wait time since you don't have to try to find some of your favorite characters in the park.
I would like to suggest that you also consider
The Garden Grill Restaurant which is also located in
Epcot. Chip 'n' Dale host this meal that is served in a rotating restaurant and features vegetables grown in The Land pavilion where the restaurant is located!
I hope this helps with your planning. If you have more questions, come on back to the Disney Parks Moms Panel- we love to help.
See ya real soon,
Anne