More reporting from Kontiki- Marc spotted this table at Kontiki, which has been built quite ingeniously. Friction locks the whole table together. There is one rope stopping the entire thing from spreading out and falling apart, running across the table (from left to right,under the table top). No lashings are used at all in this construction.
The original table was made (I think) by 1st Greenside scout troop- if you can confirm this or correct it, please leave a comment for me here. From the photo, I am unable to tell whether the legs are splayed out or parallel to each other, in the drawings above I have made them splayed so that they lock the table-top down.
I imagine that it would be built like this: lay out 4 parallel poles (the ones pointing towards the screen in the drawing and photograph) and tie together (with clove hitches on each pole).
Lift the 2 centre poles you have just tied, place the two cross-poles under these but over the outside poles.
Place table top in centre of table.
Lift table (by the two outside tied poles) and hold up (2 scouts) while the legs are inserted.
Once again, I'd love to hear from the builders of this table, and know how they actually did it.