To tamp, the portafilter needs to be placed somewhere, and it shouldn't be directly on the kitchen or table surface, as this can easily cause scratches.
 This can be solved with a tamper mat (available here in the shop for 20 euros).
 Or you have a tamper station - most of them are very bulky and take up unnecessary space.
 We stock the Eureka tamper station for three reasons:
 1) Space-saving: More or less exactly the same size as the portafilter.
 2) Visually: All metal and square, looks good next to a machine.
 3) Height adjustable for all portafilters