Lily Allen and Elton John had an on stage fall-out at last night's GQ Men of the Year Awards.
The phrase is usually "I could drink you under the table". This means that if you and I started drinking alcohol, you would be under the table before I was (you would be under the table, and I would still be standing), because I am stronger and tougher than you.
In this case, "snorting" means to inhale cocaine through the nostrils. (Er ... so I've heard).