MS Office: Change the keyboard focus without using the mouse

Another way to use the keyboard to work with programs that feature the Office ribbon is to move the focus among the tabs and commands until you find the feature that you want to use. The following table lists some ways to move the keyboard focus without using the mouse.
Select the active tab of the ribbon and activate the access keys. Press either of these keys again to move back to the document and cancel the access keys. ALT or F10
Move to another tab of the ribbon. F10 to select the active tab and then… LEFT ARROW or
RIGHT ARROW
Expand or collapse the ribbon. CTRL+F1
Display the shortcut menu for the selected item. SHIFT+F10
Move the focus to select each of the following areas of the window: Active tab of the ribbon, Any open task panes, Status bar at the bottom of the window, Your document F6
Move down, up, left, or right, respectively, among the items on the ribbon. ↓ ↑ ← → Arrows
Activate the selected command or control on the ribbon. SPACEBAR or ENTER
Open the selected menu or gallery on the ribbon. SPACEBAR or ENTER
Activate a command or control on the ribbon so you can modify a value. ENTER
Finish modifying a value in a control on the ribbon, and move focus back to the document. ENTER
Get help on the selected command or control on the ribbon. (If no Help topic is associated with the selected command,
a general Help topic about the program is shown instead.)
F1