same here, we've never had a problem bringing in food. we've brought prepared sandwiches, fruit, granola bars, water bottles, juice bags, chips, etc. we'll be doing it again at the end of this month (bringing in lunch because we'll only be buying dinners at the parks). we have eaten at the "picnic" area before, but usually we eat while we are walking, lol! no time to waste on the way to the next ride! sometimes we stop at a bench or something if we are eating a sandwich, but usually, we multi-task!
one time, we took out our sandwiches and ate at a table at the village haus restaurant. they looked so good, we actually had people walking up to us asking, "that looks good...where did you buy that?"
as long as you clean your table up when you're done, and make sure all your trash makes it into the can, they're not going to say anything to you. (granted, this was at very slow times of the year when the restaurants were almost empty - not sure if they'd mind you taking up a table during busy times. then again, they probably wouldn't notice during busy times...).