It's a garlic grater, inspired by a credit card:

Swedish chef Herman Rasmuson one day took out a credit card and began rubbing a clove of garlic against the embossed lettering. Voila! In almost no time, he had turned the clove into a uniform paste. Then, fortuitously, he decided to wash the card (not wanting to fragrance his wallet with a permanent garlic aroma), and was amazed how easily the card cleaned with just a warm-water rinsing. From there, the concept for GarlicCard was born.

Then he honed the GarlicCard into a compact yet sturdy utensil, subtly distinguished by the rows of finely embossed Gs and Cs that comprise its grating surface.