Go to the manufacturer's website and take a look at the pictures and specifications of the X1-3D (https://www.arctic.de/X1-3D...):
Table top thickness*: 20 to 55 mm
*For tables with a honeycomb structure or a sandwich structure with hollow chambers, we recommend using a stiffening plate to prevent damage to the table top.

I would estimate that there is a maximum of 6cm space for the table top to be clamped in. I have no idea how thick the top of a USM table is.