Steps to reproduce:
1. When I select Actions -> Delete in events or series I see the confirmation dialog with an empty table below that has a checkbox in front and the column headers. At least in my tests I was mislead by this as I thought I had marked a row already and did not expect to see a summary for the bulk action below.
I would expect that an Action is only selectable if something is selected.
The whole menu should probably be disabled if nothing is selected.