These things are given different names depending on their shape, but the fact of the matter is that their specific uses are conjectural.  It is known that these people worked in wood and bone as well as stone, of course, and some of these were probably mounted on handles.  Put the side scraper on the end of a piece of wood and it becomes a knife, doesn't it?  Functional ambiguity notwithstanding, the authenticity of these things is not in doubt.