I heard that late in the summer, wasps stop feeding their larvae and then begin to feed for themselves. They are attracted to anything sweet (esp. jam), which they don't consume so readily earlier in the season. I guess it's like feeding babies junk food. 😆
If you get pestered, wave you arm about them GENTLY, but presistently and they will get the message and move off. Stay calm and follow this strategy and you are most unlikely to get stung.
If you want to squish a few, flick a few drops of beer on the end of the table, wait for a candidate to land, then drop you glass on them. 😈