"Desktop" X-ray lasers have been around for a while.

And El Reg has covered one or two of them.

However the "desktop" has been the size of a small warehouse and usually worked by pumping a large current through a hollow fibre filled with gas. Strictly a one shot system.

This looks a lot smaller and capable of *continuous* operation

Not likely to be very efficient in terms of wall socket power conversion (electricity -> 500 Mid IR photons -> 1 high energy photon).