Per default the time sheet doesn't include your employee's notes. However, if you would like them to be displayed on the time sheet, you can configure this option in the settings.
Go to "Administration/Settings" and there to the area "Working Time". At "Time Sheet Report" choose "With notes". (Don't forget to save your settings!)
From now on the time sheet will include your employee's notes.
For more info about the time sheet in general see