I have researched into some typically French foods and found what I feel would be appropriate on a picnic menu:

Green Bean Tomato Salad with Herbs

Salade Niçoise is one of the great dishes of Southern France. It's the centerpiece of a summer party that's all about sunny Mediterranean style.

A Niçoise salad isn't complete without the traditional accompaniments. Serve this with Niçoise tuna steaks, mixed olives, anchovies, hard-boiled eggs and steamed potatoes tossed with olive oil and herbs.

Ratatouille

A Ratatouille is a vegetable stew from the Provence region of France. It is made of eggplant, zucchini, tomato, onion, garlic and seasonings -- usually basil and thyme.

The ingredients are cooked together until tender, or they may be cooked separately and then combined. Ratatouille can be served hot or cold as an appetizer or side dish.

Duck Liver Pâté/Foi Gras:

Foie gras (French for "fat liver") is a food product made of the liver of a duck or goose that has been specially fattened. It is a popular and well-known delicacy in French cuisine. Its flavour is described as rich, buttery, and delicate, unlike that of an ordinary duck or goose liver. Foie gras is sold whole, or is prepared into mousse, parfait, or pâté.

Quiche Lorraine

Quiche Lorraine is the original form of quiche, from the French region of Lorraine. It is an open savoury pie, filled with a cream and egg custard, and usually containing pork in some sort or other.

Selection of French cheese

- Roquefort
- Cambert and Brie
- Boursin
- Reblochon
- Pont l'Evèque

Croissants

Brief and spinach

Strawberries and Grapes

Punitions (French Shortbread Cookies)

French Baguette

Olivier cornichons

The French traditionally serve cornichons (pickled baby cucumbers) and other crunchy sour pickles as a contrast to rich foods such as cheese and terrines.

Terrine:

French forcemeat loaf similar to a pâté, made with more coarsely chopped ingredients.

Crudités:

Traditional French appetizers comprising sliced or whole raw vegetables which are sometimes dipped in a vinaigrette or another dipping sauce. Crudités often include celery sticks, carrot sticks, bell pepper strips, broccoli, cauliflower, and asparagus spears; sometimes olives depending on local customs.

Black olive tapenade

Black olives are the authentic choice for Provençal tapenade, though it's the capers (tapeno) that give this full-flavoured paste its name. Great with crudités, it can also be used as a topping for hard-boiled eggs, or as a garnish for grilled meat or fish.

Tarte Tatin:

A traditional French pastry dessert - An upside-down tart in which the fruit (usually apples) are caramelised in butter and sugar before the tart is baked.