When you go out to a restaurant the foods on the menus are divided into different sections:

Aperitivos = Appertizers

Sopas y Ensaladas = Soups and Salads

Sandwiches = Sandwiches

Plato Principal = Main Course

Bebidas = Beverages

Agregados = Side Orders

Postres = Desserts

In the exercise you have to match up  the various vocabulary items with the correct listing on the menu.