Ok all defaults. Activate the table layer. Load from alpha channel. Select the black octogon. You will now have an octogonal selection on your table layer.
Flood fill it with white for the time being.
We will come back to it later. Leave it transparent. Click on the layer palette button to see what my Layer Palette looks like. Click on the instructions button if you need a refresher on how the layer palette works. Now, toggle off the crown and the table layers, so that the only thing that remains visible is the pavilion layer.