Hello, Donna!
While Guests sometimes bring specialty items into restaurants (such as toddler food or diet drink mix for their water) you really don't need to do the same in this case. Instead of bringing in a sandwich to a wonderful restaurant such as Le Cellier Steakhouse in Epcot's Norway Pavilion, consider talking to your server about options on the menu. This way, the kids will get to enjoy pretzel bread that's served to the table, customize an entree and have a great dessert of ice cream or Le Cellier's famous (and adorable) Chocolate Moose.
Several years ago, when my daughter was still a very picky eater, we dined at Crystal Palace and asked if there were any way that we could get some pasta with butter for her (as I mentioned...picky...) Without a second thought, our server brought out an enormous bowl filled with Mickey Mouse shaped pasta topped with butter. On another occasion, my husband (who was feeling a bit picky himself that day) just didn't see anything that he liked on the menu at a Table Service location. He asked if he could order a kids' meal of chicken tenders and fries and was told that he could get a grownup-sized portion of those items instead. Again, no worries.
Take another look at the
menu at Le Cellier and think about substitutions. Basically, if a food item is available anywhere on the menu, the chef will be happy to make the switch for your grandchildren. That Elbow Pasta with Ground Turkey Marinara Sauce, for example, can easily be topped with butter. If they'd enjoy grilled chicken, but not brown rice, ask for a double serving of fresh fruit salad or some of that elbow pasta as a side instead.
We've found both servers and Chefs throughout Walt Disney World to be very accommodating, and I'm sure that you will too!
Send more questions as you think about them, Donna; we love to help!