I have washed and cut down 3 of them to normal seed tray size which gives 8x14 = 112 modules per standard seed tray. The offcuts will be cut down to fit half and quarter trays. They have a nice little drainage hole on the bottom that I can use to push out the seedling when I want to move them on to larger modules or vending machine cups. I may also try tomatoes this way next year.
These trays have been purchased for my direct cell seed sowing of onions which I'm aiming at sowing late January / Early February if it's warm enough so that once germinated I can ship them out to the greenhouse in the growhouse on the allotment or perhaps under propagator in the space saver greenhouse at home and cover with bubblewrap at night.