mgm__
Here is a gif of table detection for a scanned PDF doc (the first run is slower as it requires fetching the opencv is bundle): https://lh3.googleusercontent.com/-OobUBBtnydg/X6Vn_Ls3juI/A...
Here's a demo of the addon running outside of Google Docs: https://pdftableutil.possiblenull.com/app/
I use Tabula under the hood for the cell/row detection and it is really good given the correct mode is selected for the type of table. The modes are stream (find cells by spacing) or lattice (find cells by ruling lines).
The OCR/OpenCV seemed to be fine as well as long as the text isn't too blurry. Here is a GIF of the OCR/OpenCV running on an example Image PDF: https://lh3.googleusercontent.com/-OobUBBtnydg/X6Vn_Ls3juI/A...
I had a bad case of scope creep, so the tool can also extract tables from scanned/image PDFs using OpenCV.js and tesseract OCR wasm build!