I like to serve various kinds of breads, crackers, and alternative cracker things like pita chips, etc. with either tuna or chicken salad. This is a common meal for us when watching TV or as a picnic type of fare. Things we will have with it are cut up fresh fruit pieces, raw veggies with or without dip like baby carrots, cut up cauliflower, etc. We are also fond of potato chips.
I agree that a soup would be good but, since we basically have this as finger type food, I'd go with something that could be sipped from a cup or mug.
My personal favorite crackers and breads are pita chips, melba toast, or watercrackers.