"Appetizing" is used as a noun by itself to refer to these type of foods. Appetizing includes both dairy and "pareve" (neither dairy nor meat) food items such as lox (smoked salmon), whitefish, and cream cheese spreads. These foods are typically eaten for breakfast or lunch and, based on Jewish kashrut dietary laws, include no meat products (kosher fish products are not considered meat). The simplest distinction is that an appetizing store is a place that sells fish and dairy products, whereas a delicatessen sell meats (but not dairy products, if it's a kosher deli).
The term is used typically among American Jews, especially those in the New York City area, where one can find "appetizing shops" selling cooked fishes and dairy products in some neighborhoods with large Jewish populations. Pareve and dairy restaurants in Toronto, Canada also have "Appetizers" as part of their name who are both Kosher and Kosher style.