i would keep it really simple.
Why not just do an enormous selection of cheese and biscuits?
A good cheeseboard is always welcoming, filling and somethign for everyone. Add your apples, tomatoes, celery, chutneys and a massive variety of crackers and crusty bread, and it's as good as a meal.
Have some blues, some creamy ones, and you could even bake a few camemberts for dipping.
A giant bowl of strawberries and cream for pud.
All preparable (is that a word) in advance and you can freeze any cheese that'sl left or offer 'doggy' bags. I'd come!