You can use the arrow keys to select objects in the folders list.
In the left pane:
The up and down keys move up and down in the list of containers.
The right and left keys open and close the selected container.
Type the name of the object to select it.
In the right pane:
The up and down keys move up and down in the list of objects.
The right and left keys scroll the pane.
The Enter key opens or closes the selected container.
Type the name of the object to select it.