This, obviously, is peak picnic season. Think Glyndebourne or Henley for the poshos, think a lovely tea in the park for a day off, think a hamper or box by the river if you can get away by train (there are umpteen fabulous places less than an hour from London).
The rules are simple. Nothing too fussy to eat. Most things should be sufficiently robust to withstand being knocked about en route: so pork pie is good and a fruit cake is a better option, especially in a tin, than a strawberry tart.
