Checking the attachment list
The attachment list gives you quick access to all of the files attached to your database. This can be handy for finding the little pieces of reference material you have added to your actions and projects. It is also useful for clearing out old attachments, thus slimming your database and making it faster to sync.
To open it, just choose Attachment List from the Window menu. You are presented with a list of all of your attachments, the item that they are attached to, their size on the disk, and the date they were added.
To reveal an attachment in your OmniFocus database, double-click it in the attachment list.
To delete an attachment that you don’t need anymore, select it in the list and then click the Delete button.