After weeks of seeing my save growing and growing up to the point that it took dozens of GB in memory and minutes to load/save I posted it in the forum and Rseding91 quickly pointed out how massive the impact of this mod was (running the most recent version 1.1.4). Clearing the history reduced the size dramatically and it now takes only seconds and just over 1GB of ram. Maybe introducing a default limit in size or time could come in handy because it ran completely out of control.

you can find my original post here:
https://forums.factorio.com/viewtopic.php?p=569076#p569076

Thanks. I have been aware for quite some time that this was an issue, and I have also heard from others who haven't cleared their logs in a long while.

I am not playing Factorio much these days so motivation to fix this has been very low, but today I finally fixed this issue.

As of version 1.1.5, Train Log will now automatically clear train logs older than 24 hours.

Awesome!
It takes dedication to fix mods for a game you don't play anymore. I wasn't expecting a reply or even an update this fast :D :D