Has anyone tried to depict or decipher the stone murals in the Nordic Tombs? Are they random pictures or do they tell a story? Are they all connected?

They supposedly tell a story, hence "The Hall of Stories". To me, it's just art. Would have been nice if there was an actual story on the walls.

If they are written in the same dragon language of the walls of power of voice then it might mean something. I think it's just a conceptual sketch rather then something you can translate.

I remember a while ago about the whole bug jar conspiracy, they were "important". Would be so cool if all the murals told a story, to be at a certain location, with certain items and then something cool would happen.

They tell a story. Some of them are actually coherent, some of them not so much. They're very general and broad and usually somewhat similar. Only thoroughly looked at a few of the Dragon Priest ones though. If you look to the wiki, scroll through some of the talk pages and look over the pictures; you can attempt to read some yourself. Feels good for rp purposes.

I long for another Eltonbrand, but PCers vwould've likely solved this giant conspiracy through the creation kit.