Hi:
I would really like to give you the news that you are probably looking to read. Unfortunately, to be able to dine at any of Epcot's restaurants, including Akershus Royal Banquet Hall, you need to enter Epcot with a park ticket.
A base ticket is only good for one park per day. So if you use a base ticket to enter Epcot to eat, you would not be able to visit a different park during that same day. To eat at Epcot and be able to visit a different park that same day, you would need to add the Park Hopper option to your ticket.
If you have your heart set on a character meal, try a character meal at a Resort where park admission is not required, so you would be able to spend the day at the park of your choice. Some options include 1900 Park Fare at the Grand Floridian (usually featuring Cinderella, Mary Poppins, Alice and the Mad Hatter), Chef Mickeys at the Contemporary Resort, and Cape May Café at the Beach Club Resort.
Enjoy your vacation