How to add Notes to a task from the Update Tasks dialog?
To add Notes to a task from the Update Tasks dialog, select one task then go to menu Task – Mark on Track – Update Tasks. In the Update Tasks dialog click on the Notes… button. Type in the desired note then click OK to save the changes.
Note: You cannot add a note to multiple tasks at ones. You can format the note text by changing the font, alignment, create a list or insert an object.