This applies to both Listing Templates and Listing (aka item)
Full Editor should be used to edit one item at a time, meaning you edit items individually. The Full Editor user interface is customizable. It can be configured as a single page with multiple sections - each section one below the other. Or, it can be configured as a set of tabs. See Customizing the Full Editor
Follow these steps:
To edit one item, you can also simply double click on it. You can also click on a listing and then press the <ENTER> key on your keyboard.
To edit more than one item, from the Grid, select one or more items to edit. Click on the option "Edit / Revise Options" > "Edit one/more..."
The Full Editor window will open. Depending upon your preferences, the Full Editor window will open either In Tab Mode or In Single Page Mode.