Hi James
Dragging jobs to the bin only unschedules them. I think you want to permanently delete multiple jobs, which is best done as follows:
Go to the Job tab. Select the jobs you want to delete using the checkboxes down the left hand side of the table.
Then pick 'Edit Job Details' from the 'Choose Action...' menu at the bottom.
On the next page, tick the 'Status' checkbox at the top and pick 'Deleted', then press the Update button at the bottom.