The delete process is similar for other platforms but below are two different ways to delete a database in iSilo on a Palm OS device, such as a Treo 650.
Option One (Delete from iSilo Menu)
1) Once inside of iSilo click and hold over the database you with to delete. Once you do a pop-up menu will appear.
2) Select "Delete" from the menu.
3) Choose "Yes" to delete the database.
Option Two (Delete from inside of program)
1) Click on the program menu and choose "Edit"
2) Click on "Delete ..." option.
3) Choose "Yes" to delete the database.
http://www.pspda.com/blog/efad2go_delete_isilo_database.html