Log Elements
The Log Elements branch lists individual log units that have been placed in the 3D view as objects in their own right, each shown as element. Units that belong to a log are drawn with the log and are managed from the Logs branch of the Data tree instead, so this branch is empty in most projects.
Context menus
The branch header shows the standard group menu, and each element shows the standard item menu. Both are listed on the Standard Item and Group Menus page.