[franek]

While not built around CSV, two terminal spreadsheet tools I have successfully used in the past are sc-im and the (neo)vim plugin vim-table-mode:

https://github.com/andmarti1424/sc-im/

https://github.com/dhruvasagar/vim-table-mode

Back then I stopped using sc-im because it could not import/export XLSX, if I remember correctly. Apparently it can today!

vim-table-mode always felt a little fragile and I don't want to be bound to vim anymore. That said, it still feels like a small miracle to me to have functional spreadsheet formulas inside markdown documents – calculation and typesetting all in one place.