up arrow and down arrow

Give focus to the next or previous menu item on a menu. 

right arrow

If the menu item that has focus is a submenu, open the submenu and give focus to the first menu item on the submenu. 

If the menu item that has focus is not a submenu, open the next menu on the menubar. 

left arrow

If the menu item that has focus is a submenu item, switch the focus back to the submenu. 

If the menu item that has focus is not a submenu item, open the previous menu on the menubar. 

Return

Select the focused menu item and close the open menus. 

access key 

Select the menu item that is associated with the access key and close the open menus. 

spacebar

Select the focused menu item and close the open menus except when the menu item is a check box or radio button. If the menu item is a check box or radio button, the menu does not close. 

Esc

Close the open menus.