What is this I hear about the table tag being deprecated?

I haven't heard this. I feel I would have with my recent stretch of web conferences.

I will say tables should not be used for layout, strictly tabular data. It's the new semantic web. Maybe that's what you heard.

table tag isn't deprecated (you can look at the html spec). What you've heard of is probably tableless layouts, because tables should not be used for positioning elements on the page.

The <table> tag is most certainly not deprecated. The thing is, you must (well, should) only use it for tabular data. It was and sometimes still is being abused for layout purposes, which is extremely bad practice for a variety of reasons, and CSS is the preferred technology to use there.