The main selectable objects in Staventabs are rhythmic events and bars. And, in addition, you can select staff positions, strings in the tablature, and text in the lyrics field. The kind of the objects being selected at the moment depends on the selection type.
Selecting a single object is usually performed by a click on it. See Navigating between objects to know how to select objects using a keyboard.
If the Bars fragment is currently selected, clicking on the score selects another single bar, not a rhythmic event.
This section covers basic approaches of how to change the type of selection, and increase or reduce the size of the selected area.