JSON file
The same model, the other reader.

Reading two formats through one model
Load File picks the reader off the extension. Two formats, two readers, one table, and the page above holds no code for either of them.
They are two demos rather than one with a toggle, so both readers are on screen where you can find them.
How it's wired
Columns come from the keys of the first object. Edits stay in memory until Save.
Next: One million rows