Ok, I've been playing with the extension and added all the files with extension zip|jpg initially.
Now after a bit I've realised that I want and need only .zip extension.
How do I clear up the database and rescan the upload folder?
If I try to remove a file from the "Edit downloads" it actually removes the physical file on the filesystem where I would just like to remove them from the list.
P.S. If there is an easy way to totally wipe the "Edit downloads" page without touching the filesystem I would just rescan the upload folder looking for .zip extension and that would nicely do to me.