Spotted yesterday in a Lidl store in UK, grass mat, 1mx2m, £6.99. Top side is grass green colour (maybe a bit vivid for some tastes); underneath is dimpled (apparently to allow better drainage). Note that this is not like astroturf in that it does not have blades of grass - it is flat like the stuff that railway modellers use.
I got a couple from them last year. Make decent bases for woods and you can use them to build up ridged hills. They also did a really cheap door mat last year which is fab for plough, I use em for 15mm and 28mm fields/plough.
I have played a few games of Lart where the table top was covered by one, 120cm x 80cm, was going to do a DBA table top with some if I feel I can get some straight edges. I have used scissors to cut it, needs a good pair but was easy enough.