I did a formal picnic once for my mom and it was great! We grilled most of the food, but here are a couple of cool ideas:

Vegetable platter with roasted red pepper dip
Cheese torte with croustini's

Roasted Red Pepper Dip

Roast red peppers, peel and seed. Puree in food processor. add Sour Cream, Salt, White Pepper and a touch of curry powder. Blend till smooth. If it seems too thin add a little mayoinaise.

For vegetables I like Artichokes (great display), baby corn, baby carrots, radishes, snow peas & green beans. I usually sprinkle on kalamata olives.

The croustini's are just thinly sliced baguettes brushed with butter and olive oil (season anyway you want) and baked at low heat until crisp. Once cool they keep well in ziplock bags.