Honestly I think the smarter way is to not change the default functionality of saving in separate files, and use another tool or script to concatenate the files and put them in a format that you like better.
The reason for this is, if you have edited your experiment to use a single file, and something goes wrong, it is very very easy to corrupt the entire file, and as a result lose ALL of the data from your previous successful runs.
Search online for some examples with something like the pandas library. It’s got some great tools for this type of thing.