It is a truism to say that food is important to the French and that business entertaining should be considered a matter of great importance.
Business lunches are the most common form of entertaining business contacts with breakfast or evening events being much rarer.
Lunch is usually quite a grand affair and will usually comprise of starter, main course and desert followed by coffee. Wine will also often be served.
The quality of French food is a matter of great national pride and therefore talking about food is a national obsession. On the whole, you are much better advised talking about the food or other social issues during a business lunch than talking about business. The meal is a time for cementing relationships and learning more about each other. Business matters should only be raised during the coffee.
If inviting French contacts out to lunch, make sure you take them to a good quality restaurant and, unless you are an expert, let them chose the wine.
Restaurants usually include a 15% service charge but it is still customary to leave a small tip as well. Tipping is not compulsory in France but is recommended. (10% would be adequate.)