You can rearrange the columns, but you can't add more.
The notes (and other details) of each activity in the list are available in the preview area, however. Use the << arrows to open it from the left side of the window.
Thank you. I knew the notes could be seen in the preview area. I was just hoping there might be some way to print them.
There are plenty of printable reports in the reports area -- and the content in those is entirely customizable.