In the UK this is one of the most common foams that has potential for crafting. Polyiso (Polyisocyanurate) foam is heat-resistant, so a hot wire cutter is no use with it. A knife or saw are the typical tools.
It is a little softer than other crafting foams but this can be an advantage - rolling foil over it or pressing rough stones creates interesting textures. This also makes it ideal for the technique of making stratified rock with a wire brush.
Once sealed with PVA or equivalent, it’ll be resilient enough for scenery on a gaming table.