After playing for around 30 hours, I found that caravan card game wasn't working properly so I thought I would tidy up my inventory and put all my new playing cards in a box in the Doc's house. I'll just wait for the patch, I thought.
They went in ok.. I can still see them in the box inventory.
When I try to take any or all of the cards back into my inventory, they leave the box, but do not enter my inventory.
So... until there is a patch my cards will just have to stay in that box.
I did a test to see if it was just that box, so I put cards in another box (saved my game first this time) and it seems that no matter which box I put them into or suitcase or filing cabinet, I can not return them to my inventory.

I could be wrong but I think what you did is actually the correct way to fix the bug. In my experience when you first buy/loot a card it goes to your inventory and not your caravan hand as it should. However, if you move the items to a container then back into your inventory, the vanish from inventory and go into your caravan hand (which is what they should have done in the first place).

well what to say here?????
your cards after you took them from the box went to your caravan deck!!!
there is a bug when you buy cards from vendors that make them to stuck in the inventory instead going strait in your caravan deck
what you discover is a way to "fix" this bug lol

Good place for them!
(Or tossed into a campfire perhaps?)
Stupid cards - they caused me no end of grief...
Well actually, now that all my cards are gone, so is my grief and problems!
Stupid cards.
L8R

Actually, the first time I tried that container fix, they all disappeared; no deck showed up. Reloaded, tried with a different container (or maybe even my companion, I forget) and it worked OK.