The tabs are to flip the pedal over with your toe as you slide into the toe clips. Toe clips always weight the pedal so it ends up upside down. The side you have up in the right hand picture is the bottom of the pedal. Actually unusual to have two off-center tabs like that right set. The tab on the inside of the pedal is to direct the toe strap upward around your foot. Otherwise the strap (at least when your foot is not in it) will catch the crank arm and prevent the pedal from swinging freely.