The answer to this is relative to the time and cost inputs. If you are a small company and bootstrapping, then no, it's unlikely to be worth it. Better to skip the table and just hustle to meet press/investors/other startups, since $2k can go a long way elsewhere.
My advice is to go to the hackathon the weekend before and build "something" with your cofounder (presuming you have one). This should* get you two free tickets to the conference.
Someone else here mentioned that if you sell to startups it might be worth it - I'd probably agree with that as an exception if you aren't already based in the Bay Area.
* You would have to confirm that Techcrunch are still offering this. They're usually pretty quiet about it (for obvious reasons) but I've used this method both times I went (for free).