This is the front and back of a "Pencil Board". But what is it really? Is it a hard pad so you can draw in bed? It is supposed to go between the page of the notebook you are writing on, and the next. This avoids press/bleed through of inks. But if you're using pencil, that doesn't bleed. And if you don't stab down as you write letters, you're not going to engrave the paper anyway. But it's Sonic X, and it's interesting to look at, so...
You can find them occaisonally for fairly cheap, as they are just cardboard with lamination.