Maybe someone knows of a more current pad similar to what you're looking for. I've got an older hard surface mouse pad made by allsop, it has a rigid metal frame with a teflon type coated pad surface. I imagine that's what you're talking about, something rigid to act as a makeshift 'table' rather than a flexible mouse pad which will curve and sag on something soft like the bed.
Keep in mind that not all 'hard' mousepads are rigid. Some are 'smooth' surface or considered 'hard' surface but lacking a rigid frame and still rely on a desk or table to maintain their flatness. As opposed to a 'soft' mousepad with some sort of cloth.
Another thing you may want to consider as an option is use something like a clipboard, rigid piece of plexi or wood like shelving material and cut to the size you need (or have cut if you get it from a hardware store). Then use that as a support with a standard mousepad on top of it. The reason I suggest that is a true hard gaming surface can be brutal on mice after awhile. I went from the old hard surface back to a rubber backed cloth pad (steelseries qck) after literally wearing the feet off my mouse. Replacement feet cost almost half what the mouse originally cost. I've had mice die after a few years, some sooner than others due to mechanical failure but using that rigid pad was the first time I've ever worn the feet clean off leaving the mouse scraping/dragging along the surface.
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