Default Objects
appear at the top of the object panel - this includes the main camera, reference height (to help you build your scene to life sized proportions), Direct Light, and the Orbit Flag.
Object management
The objects panel allows you to view all objects in the scene, select or group them, toggle visibility, duplicate, or lock them.
To select multiple objects, ctrl+click (or ⌘+click) the object names in the panel.
Right clicking on objects in the panel will open options to group, duplicate, rename, lock, and hide objects.
Double clicking the object name in this panel or in the object properties panel will also enable renaming.