Interesting. I just looked at the page source and it is in fact using a table layout. I always assumed it was an image map, which I assume would be even more obscure for the LLM.
We should check the Wayback Machine, but in my memory this was built with an image map. Maybe like, 10 years ago or something. I was googling around when writing this post and saw that there are folks still tasked with making sure it's up and running. I wonder if they migrated it to tables at some point in the last decade.