WPTools differentiates cell selection and area selection. When cell selection is used deletion of the selection will clear the selected cells.
If whole rows are selected, the selected rows are removed.
In case of area selection it will delete whole tables only if the start and the end of the area are outside of any table. This is why nothing happens in your example.
I haven't thought about this yet, but it would make sense to expand the start and the end of such an selection to select a whole row. This may be a feature for a future version.
We are working with generated documents which contain text and several small tables.
If the user makes a selection containing only parts of a table by mouse or keyboard and then presses DELETE, nothing gets deleted (sometimes the content of the first cell in the selection)