The Page Up / Down Tool is a tool in Isle of Tune used to view the next/previous pages in the View Shared Islands List. It is an arrow pointing to the top or bottom (depending on if it is page up or down). Click on the View Shared Islands Button, then the view shared islands bubble should appear. In the bottom-center part of the bubble, you can then find the page up and down buttons.
Warning! This tool is limited to the Website.