4 stands made to mount on top of a Kallax 2x1 stood upright to accomodate a table/desk on top of it.
This one specifically is meant to make use of LoneWolfWagen's Svarta Desk files and creates a connection surface at the exact height in combination with the taller blocks, but could be used on its own as well.

Use a (4 in total) m5x20 countersunk head bolts and locknuts to connect to a Kallax -countersunk on the Kallax side after drilling 5mm holes.
Use 3 (12 in total) screws, preferably 4x16 panheads, to screw into your table.

Heads up, you want to in-set these a little bit from the edge as otherwise they unfortunately sit directly above the Kallax's own screw taps. On the bright side, this hides them from view a little and looks somewhat more elegant.