One of the best things I ever did was buy a polyethelene cutting board and putting it on my tying table. Glues don't adhere to it (even superglue just peels off), it is non-glare, and is a nice white color for great contrast. It would be easy to attach one to a portable tying table by simply cutting it to fit and attaching it with screws.
Since I don't use a portable tying desk or table prefering to tie on a larger surface on which I can place all the materials I'm using for a fly on and keep them separated for ease of finding and handling, I use a 4' long folding table I got at Office Depot for about $25.00. It is 30' wide and easily accomodates my tools, a lazy susan I use to put freshly head cemented flies on for drying, the material to tie the flies, etc. I have a piece of 2x4 that has holes drilled in its edge (the 2" side) that hold my bobbins (I have over 30 of them all loaded with different thread colors or sizes), bodkins 9I have 3 different sizes), dubbing twister, dubbing teaser, and wjhip finish tools ( I ahve both the standard and long-reach Materelli) that I place at the back of the table next to the wall. This way I have all my tools readily at hand. I place my cements (I use Flexament, head cement, superglue, and Loon High Gloss) just in front of the 2x4 and up against the back edge of the polyethelene cutting board, which keeps them handy but out of the way until I need them.
If you want a table to take with you on fishing trips, a polyethelene "TV tray" table is idea. Inespensive, very portable, easy to set up, takes up very little room, and can be set up for use nearly anywhere, unlike the portable tying desks. Moose, you might consider getting one of these for your use, although it won't fit over the arms of your chair, it will fit right next to it and provide a pretty stable surface for tying.