Food usually looks best in its natural habitat; I think it's a mistake to shoot it in a "Sears portrait studio", isolated sort of way. When you shoot food with nothing but a backdrop/tabletop or a sweep, you lose a lot of the visual cues that tell the viewer that the food is delicious. Baked goods, for instance, often look their best surrounded by the trappings of baking: a bowl of eggs, a sack of flour (like anybody actually uses fabric sacs at home anymore), a few vanilla beans, or what have you. Plated main dishes look best in a place setting, complete with flatware, beverage, napkin, perhaps candles and/or a centrepiece, and so forth. I'd have been a lot more liberal with the blackberries, for instance, and had them surrounding (but primarily behind) the bowl.

That means, among other things, that your surface doesn't need to be nearly as large as it might seem at first. In some instances, you can sort of build a "backdrop" of associated goodies that rises out of frame at the back. In others, you can let the table come to an end, with an out-of-focus background that lends an ambience to the setting. That out-of-focus background can be quite fake, as long as it looks right in the picture. (A piece of cheap tan or light brown paper/cardboard and a few shiny things, if they are well-blurred, can simulate a wood-panelled dining room with Michelin stars well enough that very few will be able to tell the difference.)

Your actual surface should vary with the food you're shooting. For some things, you'd want a very plain, honest, rustic wood surface. That would probably be the table you're setting up on (and you can make that a modest-sized folding table). Beyond that, you're looking at tablecloths (or cheap fabric that can pass for a tablecloth if nobody needs to see the edges), tea towels, napkins that look good on camera (they don't actually have to be OMG-expensive linen) and the like for some shots. For others, you might want to try matte- and gloss-laminated woodgrain, marble and granite prints. (That was a lot easier twenty-five years ago when you could get tacky vinyl sheeting almost everywhere in almost any pattern imaginable. A sudden and inexplicable upswing in taste among the masses has made things unnecessarily dificult for us.) You might find that a couple of different large-ish tiles of natural stone from your local home renovations store come in very handy for some shots. You can actually tile them and clone out the seams in your favorite editor if you need a bigger surface, but you'd need a sturdier table/counter than the cheap folder suggested above.

As for the grey card: you don't need anything big. A dot the size of a dime is more than enough to white balance with, and you can put it just about anywhere in the frame and either crop or clone it out.