As far as we know, there's no agreed-upon record of the largest-ever casino tip. Toking is often a private matter and many "Georges," the gambling term for big tippers, don't want the size of their tips spread around.
But according to Whale Hunt in the Desert by Huntington Press senior editor Deke Castleman, the largest known tokes in the modern history of casino gambling are attributed to Kerry Packer, the richest Australian. Here are a few examples from the book.
Another famed big tipper of recent times is Hollywood actor Ben Affleck, who twice allegedly distributed tips of about $150,000 after winning big at the Hard Rock. During their engagement, however, Jennifer Lopez (a.k.a. "J-Lo") apparently clamped down on her fiancé's legendary toking habits, earning her the nickname in Vegas of "Pay Low." According to Norm's Vegas Confidential column in the Las Vegas Review-Journal (12/06/2002), during their Thanksgiving holiday visit that year the couple were playing baccarat at the Mirage and Affleck tossed a $5,000 white chip to the dealers, only to have J.Lo pronounce "No," retrieve the chip, and exchange it for three black $100s.