Big restaurants can only be called 饭店, such as 北京国际大饭店. Smaller ones can be called 餐馆，饭馆，饭店, such as 洋洋餐馆，茂荪馆饭馆 ，双塔老饭店. And there's a 餐厅. 餐厅 means a restaurant or a dining room in a building. The building can be your house or other buildings with other functions. 俄罗斯飞象西餐厅