Here are plans for a picnic table you can build yourself with simple hand tools and some cheap lumber (including bolts and screws, plus a bit of rope to strap this all to our bicycles for the trip home, we spent $50). Protect the wood with linseed oil or something similar and you’ll be able to leave it outside year-long without it weathering badly. If the wood you buy is warped, your table will be wonky too.
The plans are available formatted as a PDF or PNG document. You can also download the original SVG file, which might not render correctly in your browser. Our thanks to Arnold Franssen for the original version of these plans, which we modified only slightly.