Dining at resort TS, non-buffet restaurants either RIGHT when they open or at the latest seating for a meal are when they are going to quietest, in general. For the restaurants in MK - again - unless dining at off hours - are all noisy, in my opinion. Sure, right at 11am when a QS place visit opens for lunch - it's going to be quieter than at peak between 12-1:30.
Also - time of year, other parks you plan to visit, if this is a child or adult we are talking about, boring or adventurous eater, where you are staying (on or off-site) - and whether or not you will have a car can influence suggestions I could give.