Does UV-mapping generate for some points of the 3D model several points in the 2D projection? Assume my 3D model is a pyramid with a rectangular base and I numerate four corners of the base with 1, 2, 3, 4 and give 5 to the top point. If I project this pyramid into a 2D star-shaped object, would not all four outer points of the star be associated with the point number 5 in the 3D model?
The way it is usually defined, every vertex in a mesh corresponds to a UV-coordinate, and there must be exactly one such coordinate per vertex, because that is how a renderer would fetch texels. So it is impossible to have multiple UV coordinates for a single vertex unless you have multiple parameterizations for your mesh.

However, meshes often get split up during parameterizations and the same vertices can end up in multiple locations, just like in your example. Most often, those vertices are simply replicated while loading/rendering so the vertex-to-uv mapping remains 1-to-1 or many-to-1. So a renderer will likely interpret your example as the following (v5 is split into 4):