If it is just to update data, then I would assume you would just upload the json file, as long as all the field names are the same and the file name is the same, then it should just over write the old file.
Hi.
If you can work with JS, you can probably find some JS library that does this all on client side.
You could integrate with Wappler’s components using variables/arrays.
Else, you can create a custom module which would read the uploaded JSON file and return its contents as an array. You can then use this response for binding in tables directly.