170 MB seems like a lot. Aren't there less than 1,000 different states? My first naive idea would be to link to a static version of the gameboard further down the page like href="xo-------".
Each tile can take on 3 states, x, o, and the empty state. 3^9 = 19683. Of course, this is also counting many invalid states where a player would have won and symmetries of the board.
It looks like there are only 5,478 valid unique games states.