Wikipedia: menu
In a restaurant, a menu is the list of options for a diner to select. A menu may be a la carte or table d'hôte. The items that are available for the diner to choose from are broken down into various categories, depending on the time of day or the event. A breakfast menu in the Western World has eggs, toast or fruits to help the diner have energy to start the day. Grain and protein are considerations as well. Lunch and dinner menu items are often larger portions of food because one becomes hungrier later on in the day after consuming energy. A degustation menu however may combine elements from breakfast, lunch and dinner.
In Mary Douglas' article, "Deciphering A Meal" she asserts the menu is very important because it is the basis of all society. Through picking items off of a menu, one can learn a lot about a person. If they choose meats or high-protein food, it demonstrates their activity and need to replenish their energy supply. On the other hand, if the items chosen are vegetables or dessert, one could conclude that the person is a vegetarian or they like large amounts of sugar. While this does not apply absolutely, it may give insight into the lives or people by what they order. You can now get interactive menus and booking service, like OnlineMenu.