I've used a picture dictionary when I first visited Japan. It worked out pretty well, and it was divided into categories so it was easy to find the item/word you wanted.
They have a Korean one:
UNSPSC Code: 55101500
Not cards, but I have a copy of This, Please, which lets you point to a picture of the thing or activity you are interested in. To go with that, you could perhaps make a card with translations of
I am unable to speak