Being able to do something like:

{{ read_csv('path_to_table.csv').query('population < 10000') }}

Might simplify a setup considerably.

I'm not sure if it's a good design choice though. You could use a hook to preprocess tables also (see preprocessing tables using hooks), which is probably a better design pattern (because then you don't have any data logic inside your documentation code, it's just input/output).

If you read this & have a use-case for this, let me know!