I started out with three (note the sizes also in feet & inches for the metrically challenged!): one 2035 x 700mm (6' 8" x 2' 4") and two 820mm (2' 8") wide. I cut the smaller one down to fit across the end of the other two laid flat, making it 1640mm (5' 5") wide. Joined together you end up with a table area of 2760mm (9' & 1/2") long by 1640mm (5' 5") wide.
I apologise for the crappy photography!
In order to stop them sliding around I put some latches on the edges at the joints which are held in place by simply dropping a broad-head nail through! Cheap as chips but effective.
Note that when I cut off the bottom part of the door I left enough for a piece of framing timber to be cut and screwed into place to finish the leading edge. A bit of masking tape covered the join.
All that was left after than was a couple of coats of Dulux acrylic - in a nice dark olive green - a viola! one instant wargaming table that fits nicely over the top of the table-tennis table! The beauty of it is that it can be easily taken apart and stacked somewhere out of the way - especially if somebody wants to play table-tennis rather than wargame. Crazy talk I know, I mean... who would eh?
Now if I can just get the rest of the crap out of the garage I "ll be able to put on that wargame...