Camera on lap tray

Hi I have my camera on a lap tray, because am hoping to stop fungus getting on the lens. Should I put something over it to keep the dust off please?

I would not cover it. To prevent fungus you are looking to have good air circulation and light.

OK what's the best way of cleaning it please?

If it stands long enough to accumulate dust, a soft cloth or brush, as you would an ornament