Thanksgiving normally brings family and friends together around the dinner table, but only a Sacramento Thanksgiving brings them together around the Capitol Mall roundabout, whooping and yelling on bicycles. Give thanks for the Appetite Enhancement Bike Ride. The annual underground bicycle parade attracted over 500 people to the California Stage early Thursday morning. R and 25th streets were littered with road bikes, penny-farthings, low-riders, vintage cruisers, every bike imaginable, plus a giant toaster mobile. DJ Larry Rodriguez' international beats and raffle ramblings rang out over the block. What started out as a casual ride with a dozen bikers 21 or 22 years ago — no one can rea