Apple Numbers '08 - Manual (Page 30)

30 Chapter 1 Numbers Tools and Techniques
Keyboard Shortcuts and Shortcut Menus
You can use the keyboard to perform many of the Numbers menu commands and
tasks. To see a comprehensive list of keyboard shortcuts, open Numbers and choose
Help > Keyboard Shortcuts.
Many objects also have shortcut menus with commands you can use on the object.
Shortcut menus are especially useful for working with tables and charts.
To open a shortcut menu:
m Press the Control key while you click an object.