The object handles are the lables that you can see in the game area linked to items and mobiles around you. To activate the object handles, you have to press the buttons CTRL + SHIFT, and the labels will stays visible until those 2 buttons are pressed. Releasing the buttons will makes the labels disappears.
You can make a specific label disappears by Right-Clicking over it. NOTE: right now there is no way to change the hotkeys or to make the labels to stay.
With the action Switch Object Handle you can also set a filter so you can search specific labels by name.