Yes, it's the Tonson Night Market in Mahachai. This is not the famous Mahachai Market on the train tracks.
I was amused to discover a tourist website which doesn't even mention the train, but suggests you can get there by boat:
"Head to the nearest Chao Phraya River pier. Take a boat heading towards 'Nonthaburi' or 'Wat Rajsingkorn' and disembark at 'Mahachai' pier. From there, walk straight for about 10 minutes, following the signs towards Mahachai Market."
DON'T TRY THIS AT HOME! 😆
(for those who don't know, Nonthaburi and Wat Rajsingkorn are at opposite ends of the Chao Phraya Express and it goes nowhere near Mahachai.)