I have a favorite but it doesn't fit your size requirements. Here it is anyways , "Camping & Wilderness Survival" by Paul Tawrell, Distributed by Gordon Soules Book Publishers Ltd www.gordonsoules.com . The book is 8"x10" and 350 pages. It does cover virutally everything you need though.
I have no reccomendations regarding your original query, but the folks here are generally very experienced and knowledgeable. If they don't know it, they know someone who does and are free and generous with good info.
And, by-the-way, welcome to Armslocker.
Have your local library use the Interlibrary Loan system to get copies of all of Euel Gibbon's books. Stalking the Blue-Eyed Scallop, Stalking the Wild Asparagus, and at least two others. Do a search of the used books at Alibris Books and Amazon.com, too. You can get large format, beautiful pics, actual BOTANICAL textbooks, too. You need to be able to recognized the main food plants, all 4 seasons, so that you can note where they are, even if it will be months before they are edible.
There are several books, like Weeds of the West, that help in identifying plants very well, but you'll have to consult another book that shows how to use them.
You'll find that a lot of wild edible plants are also used as medicinal herbs and that if you eat too many of them, you'll get an overdose of the natural compounds that they contain which domestic crops do not. Wild plants can be very hard on your system, especially when you are not used to them.
You HAVE to practice this stuff ahead of time, as it's not just a '1,2,3' mechanical affair but an art. A book is a guide, but it can only get you started. The beginning of a crisis is already too late to learn.
After trying to live on wild plants, you'll find the reason why the Indians truly valued good hunting and fishing skills.
actually there's not much to it, if you are willing to be bored. Pine inner bark, cattail tubers, camus roots, dandelion roots, acorns are everywhere and easy to harvest and prepare, but they are pretty tasteless.
It sounds as if you haven't had them. They're generally relatively tasteless. Frying them in garlic or onions is probably the best way to have them, but they can be dropped into stews with little effort. Slugs are a bit chewy, though...a bit like eating a bit of rubber. Much like escargo, though, and garlic and butter fixes 'em right up if you have it. Wild onion is very, very common in much of America...if you live an area where it grows, you'll probably be using it a lot to season up what foraged material you've collected.
Plants are generally bitter, and frequently require boiling with several changes of water to mellow them out. If you like things like spinach and collard greens, wild plants will probably taste ok. I question the knowledge of anyone who say that inner pine bark is "tasteless". It's usually permeated with resin and pretty pungent. If you're down to eating pine bark, you're in pretty dire straights.