The Workbench allows you to create bookmarks in files that you edit so that you can quickly reopen those files from the Bookmarks view ( Window > Show View > Other... > General > Bookmarks).
You can reopen the file for editing at any time by double-clicking the bookmark in the Bookmarks view.
Creating a bookmark for an entire file
Deleting a Bookmark
Adding line items in the Tasks view
Associating a task with a resource