I once made a netting thingy that covered from my head down to my waist, with elastic around the waist, and which was large enough to allow me to eat dinner inside it without the pesky NZ sandflies biting me, and that worked well. I have subsequently worked out that sandflies (and mozzies) cannot bite through lycra, so use lycra socks and gauntlets to protect the limbs, and cover most of my head with a buff, and that is more practical for me........however, I'm not sure what insects you are wishing to exclude from your dinner.
Alternatively you could do as NNW suggests, and use a Faraday cage, although I thought they were more useful to stop people inserting thoughts into your brain (or, have I overinterpreted NNW's post?!).
However, rather than MYO foil helmet, you can buy this
http://www.aliexpress.com/w/wholesale-a ... elmet.htmlwhich allows you to use it as a helmet, cook in it, eat from it, AND use it as a Faraday cage, but not all at the same time, and none of which prevent little creatures from sharing your dinner!
A