Very high RAM usage when visiting flyertalk.com website

Whenever I'm on flyertalk.com, my RAM usage spikes super high to the point of affecting system performance. Firefox never causes a slowdown otherwise and my typical usage involves hundreds of tabs opened without issues with 8 GB RAM.

At first I didn't think much of it--it could be a Firefox update or a poorly designed site--but the issue has been for a while now. As soon as I leave the site, system performance is restored. Performance impact is affected even when all my other Firefox tabs/instances are closed.

I'm curious for those with a programming background if that site in particular relies extensively on some technology like Flash/Javascript/etc. that might be the culprit. I do have an extensive list of about:config settings but I haven't been able to narrow down the problem yet.