Tabular-data describes a collective form of definite information. A form is not "tabular-data", it is interactive and not even really information for the visitor of the website, rather, it is information that (usually) gets sent, therefore it's fair to consider it incorrect to view changeable forms as "tabular-data." (Then again, it really depends on the usage, but I'm assuming you mean forms as in the practical and semantic purpose).
As far as a practice for styling forms, I usually tend to use divs and ul li combinations, as a form element is in fact a list of information. It even comes with (very limited, but still) some formatting options such as fieldset, legend, etc. I would consider looking into those as well.
Then there's the other side of the force (not necessarily the dark side, just, the alternative side) where semantics, while they matter, shouldn't be turned into a religious discipline. If tables work for forms, then so be it. You cannot apply a single set of semantic rules to every single situation. I've found myself saying this a lot, lately, but I'll say it again, every situation is different.
