First don't delete files in the System Files section of the virus chest as these are back-up copies of system files in case they were to become infected.
There is no rush to delete anything from the chest, they can't do any harm there. Anything that you send to the chest you should leave there for a week or two. If after that time you have suffered no adverse effects from moving these to the chest, scan them again (inside the chest) and if they are still detected as viruses, delete them.
Inside the chest is a little like the windows explorer in that you can highlight (select) multiple files at anyone time and using the right mouse button (or the Menu File) select an option, Scan, Delete, Restore or Extract.
