Competitive table tennis has rules on racquets, but you may use one of any size, shape or weight as long as the blade is flat and rigid, however, at least 85% of a blade's thickness must be made of natural wood. The inside of it can be reinforced with material like carbon fiber, glass fiber or compressed paper as long as it's not thicker than 7.5% of the blade's total thickness or 0.35-millimeters, whichever is smaller. Make sure the side of the blade used for hitting the ball is covered with ordinary pimpled rubber and the blade is matt, bright red on one side and black on the other. Also make sure you are comfortable with your racquet and can get a good grip on it. Blades can be bought separately from the rubber and racquets also come in various materials.
