Object list layer
Is the menu that allows you to control your models that are listed in the object list.
Duplicates an object to the same position. Shortcut CTRL + D.
Hides an object from the scene. Shortcut CTRL + SHIFT + H.
Locks an object - you are still able to see it and select it through the object list, but its not selectable on the canvas. Shortcut CTRL + SHIFT + L.
Deletes an object. Shortcut DEL / BACKSPACE.
You can double-click on an object in your object list to rename it.
Convert to geometry
Converts the object to mesh geometry so you can edit it. It applies only to parametric objects.