The largest playing card structure is 10 meters long, 2.8 meters tall and 3.5 meters wide and was created by Brian Berg in the US in March 10 of 2010.

Actually, I have to correct you right there. The largest playing card structure was the deck Eyes of Blue for Yu-Gi-Oh! released in 2009, containing approximately 48 cards when a modern structure deck is limited only to 20.