if you have 10 blocks across at 12" each block that's 120". so you're talking about a tablecloth at 120 x 120? how big is that darn table? that's kingsize.
if you add sashing, my goodness, you could tablecloth your entire dining room :D.
have you thought about two items instead of one? if you go 5 across you get 60". you could get two of those 60" squares for tablecovers. if you add sashings and/or borders, you can make it bigger.
with a little imagination, you could make quilts for two single beds.