Ah, yes! Critical to know the magic names of things.
That is a Seklema mat:
You can make a passable, less-expensive alternative for some uses with a piece of MDF or similar and a temporary spray adhesive. When I do that, I typically use the spray adhesive for holding down t-shirts while screen printing.
You can find a lot more info by searching on “seklema” here (both about Seklema mats and the alternatives).
Some folks have even built their own vacuum tables to hold down paper and other lightweight materials.