In the US, one would say, "put the groceries on the counter." Counters also exist in a store (e.g., display counters where items for sale are placed) or in an office, referring to flat surfaces that are not free-standing with legs. Typically a "counter" is wider than a "shelf" and is neither very high or low. A "work surface" is a very general term that applies to the top of anything where "work" can be done. For example, in a restaurant, a boss could instruct the employees in the kitchen "to clean all work surfaces at the end of each day." This would apply not only to the "counters" on which plates of food are assembled, but also to the surface of a stove or a wooden chopping block where meat is cut. No one would say, "put the groceries on the work surface" when referring to doing so in a kitchen.