Use Tab to navigate through elements on the page,
and click Enter or Space to select the element.
Alt + Up:
Select previous item in Library Tree.
Alt + Down:
Select next item in Library Tree.
Alt + Left:
Collapse the currently selected Folder/Album if it is expanded or Move to the previous Folder/Album (if available) when the current Folder/Album is collapsed.
Alt + Right:
Expand the currently selected Folder/Album and move to the first item within the folder/open album content.
Left or Right : select content one by one.
Alt + S: enter Multi-Select mode in the main library. Select Alt + S again to select all assets.
Alt + T: Quickly select additional options toolbar:
ESC: Exit Multi-select, Preview/Information page, and Dialog windows.