COLOR PHOTOPHOTOGRAPH BY BILL FRAKES FIRST DOWN   Whither Lester Speight--a.k.a. Terry Tate, the overzealous "office linebacker" who tackled coworkers in Reebok's 2003 Super Bowl commercial? He was back in action on Sunday during a pregame skit in Tennessee. After a "ref" announced the Titans would be penalized if fans got too noisy, Speight (who played briefly for the Giants) stormed out and sacked the official. The crowd roared but was later hushed, as Tennessee fell to the Jaguars 15-12 in the final seconds.