It is possible to create multiple tickets using a single JSON file, however it's not the simplest thing to do and can take just as much time as creating one ticket per JSON file.
I'd personally recommend creating one ticket per JSON file unless you want to do some custom development to make it work smoothly without causing any discrepancies to the data.
Thanks for the reply.
What do you mean by "custom development"? I assume that if it is possible, it should just be a matter of formatting the json file properly, no?