Let the user select multiple entities by clicking on one entity's selection radio button and drag the mouse pointer down the list.

[raindropsfromsky]

If the user wants to select multiple entities in the Entities list, he has to click on the selection radio button of each entity separately.
If the entities are contiguous, let him select multiple entities by clicking LMB on the radio button of the first entity, holding LMB down and dragging the mouse pointer over the others, as shown below.

Currently, Sketcher allows us to toggle the visibility of multiple entities (click and drag over the "eye" icons).
But we can't do that on the selection radio buttons.
So the idea is to extend the same feature for multiple selection.