Its fake, he is standing well away from the table making it easy to just put another guy there and add bruce lee in.
The background is clean and can be edited really easily.
Also Lee's face wasn't shown and so someone can imitate him easily enough.
Bruce Lee was amazing, just as good as Ip maybe even better. I have read all three books about him and his films and he was extremely talented. Most of his moves were actaully real in the films.
Still that video is pretty cool to watch