So did you guess correctly then?
18 x 9" blocks (finished size) to stitch into six rows of three - then a 1.5 or 2" border all round.
This is a 'Buggy Barn' star pattern that was originally a 12" block that I resized down to 9". You just stack up your fabrics, draft the pattern with all the cutting lines onto freezer paper, iron that onto the top piece of fabric and slice through. Then by moving the top layer of star pieces to the bottom of the pile you end up stitching a series of contrasting stars.
Once I've quilted it I think I may well round off the corners before binding it. Then I'll add ties at each side to keep it from sliding off the table.
It's a bit on the bright side but all three kids love it and it will brighten up that corner as well as protecting the table.
Sarah did make me smile as I was pulling out the random fabric choices - "Oh no Mum," she said of one selection "You can't use that one it's far too nice!"
Spoken like a true quilter :o)