On the top of the tab there is the "Refresh" button to refresh the deleted files list manually. Also this button has got the dropdown menu to set option for automatic refreshing.
On the bottom panel there are the "Recovery" button and the "Delete" button.
The "Recovery" button is used to recovery deleted files to the folder where that files have been deleted. If the destination folder is not exists anymore the program will ask you where you want to restore file. You can select multiply files for recovering.
The "Delete" button is used to delete files permanently. You can select multiply files for deleting.