Depends on the type of graphite. Isotropic blocks can be 1500mm x 1500mm x 300mm at the largest and extruded or moulded blocks could be 600mm x 600mm x 2400mm long.
It is difficult to make a list but almost every object we come into contact with every day will have been in contact with graphite at some stage in its production cycle, anything from needles to nuclear reactors.