Power lunchers at the Four Seasons on Friday looked on as Martha Stewart sat at one end of the Grill Room with J.Crew Chairman and Chief Executive Mickey Drexler, while Sam Waksal, founder and former CEO of ImClone, dined on the other. When lunch was over, Waksal left without a word to Stewart — but it’s not clear whether either knew the other was in the room. Waksal served nearly seven years in prison for insider trading, and Stewart did five months for obstruction of justice in connection with the case. Stewart’s rep declined to comment. Waksal couldn’t be reached.