Yeah there was a period of time when IE didnt support display:table and ARIA hints wasnt as developed. So if you wanted to create accessible web sites with nice layout you had to resort to weird hacks, often using floats.

Floats was never intended for that purpose though, it was just a desperate hack to get around IE limitations.

But html tables was not a viable alternative for organizations which was required to have accessible websites.

(Today I believe it is possible to create accissible html tables through ARIA hints, but that was not an option at the time.)