TABLE elements were proposed before that (and implemented in other browsers as well). TABLEs were part of the HTML3 draft. Unfortunally, Netscape only implemented a subset of the TABLE functionality, and an incompatible subset as well. Other browsers decided to be Netscape compatible. HTML3.2 specifies a (compatible) superset of the Netscape implementation, and there's even an HTML tables RFC. Both HTML3.2 and the RFC date from 1996, IIRC.

Unfortunally, we're a decade further, and little progress has been made.