I did not know 1" thick masonry tabletops were vulnerable to sudden cracking. Masonry bathroom vanity tops are typically that thickness, aren't they? Is the risk because it's outdoors and subject to changing temperature extremes?
If you built the support structure so it featured a (well-hidden) sheet of OSB or plywood glued right underneath the masonry, and then a sound wooden structure under that, then even a through-crack in the masonry wouldn't be catastrophic.
That said, another possible use is to artfully score it and then break or cut it into pieces and use the pieces as pavers to make a kind of stepping-stone path.