Excel

To select the whole of your data quickly click anywhere in the data and use Ctrl * (from the numeric keypad)

Word

Use F4 to repeat the last action, ie if inserting rows in a table press F4 to repeat inserting rows (can use this in Excel too!)

PowerPoint

If you want to make a font, colour, bullet change to your whole presentation switch to the slide master by selecting View, Slide Master - make the change and then close the master from the toolbar that will be showing.  The whole presentation will be affected.