bed tray?

Maybe you're looking for something like these?
http://www.thuiszorgwinkel.be/store/nl/catalogsearch/result/?q=bedtafel
The first table can carry about 15kg so a laptop should be fine. (sorry the website is only in Dutch)

This is the online shop of a 'ziekenfonds/mutualité'.
If your ziekenfonds also has this kind of shop you can get a discount on one.

I hope you get well soon.