Those are the horizontal stabilizer pitch trim wheels.
When the horizontal stab (or THS as Airbus refers to it meaning "trimable horizontal stabilizer) moves from inputs from the autopilot or control switch on pilots yoke (A300-600), the movement feeds back to the trim wheels to show that the stabilizer is moving.
The trim wheel has another function as a standby control to the THS. By moving the trim wheel, this will override the electrical controls of the THS and mechanically control the hydraulic control valve to move the stabilizer.
You're only as good as your last departure.