Senior managers socialize only with those of equivalent status. Business entertainment is done mostly in restaurants. Lunch is still considered a private time. However, working lunches and breakfasts are becoming more common in France. The French do not like to discuss business during dinner.
Dinner is more of a social occasion and a time to enjoy good food, wine and discussion.
Spouses are not included in business lunches, but may be included in business dinners. A female guest of honor is seated to the right of the host. A male guest of honor is seated to the left of the hostess. Never start eating until your host and hostess have begun. Wait until toast has been proposed before you drink wine.