Instead of clicking an object, an object may have a keyboard shortcut.
To provide a shortcut, you have to provide a combination of keys, one of this must be or CTRL or ALT or SHIFT (the check boxes in the shortcut voice).
To test your shortcut go to Development->Suspend Development tools, otherwise IDE shortcuts will block your script shortcuts.
You can provide also an hint, to explain to the user what is the short cut (it is accelText property). This will appear as a text in the object.