A bad habit in many bars and restaurants in our country is to translate as sandwich any type of cold meat or other filling that goes between two slices of bread, when really only very few sandwiches are made with sliced bread. Basically cheese and ham are made with sliced bread, some of the cold vegetable type, with lettuce etc. with mayonnaise and with mayonnaise and tuna.
Most sandwiches are made either with baguette or with round or elongated crusty rolls, in very few places you will find this type of food specified in its English name of ROLL