Well...it's Will Tsai, so what do you expect.
If you want someone to explain it to you, here's what happened:
There were 5 coins on the table. They were organized in piles of 1-1-1-2. Will took an apparent ungimmicked card from an Ellusionist White Arcane deck and placed the card on the first pile. With magic, he flipped the card off the first pile and onto the second pile. Suddenly, the coin form the first pile was gone. He repeats this process until all the coins are gone. Afterwards, the rips up the card used into shreds.
If you want to know how it's done, beats me! He either used a gimmicked card, gimmicked coin, or any other gimmicked device. All I know is that the trick is either gimmicked, or he has really, really good palming skills.