detect a table part from entire image in python

I have an image of size 3500x5000, now I want to detect only the table part from the entire image and crop and rotate it if it is not straight for OCR processing. After all search, I get an idea for cropping each cell in an image using https://medium.com/coinmonks/a-box-detection-algorithm-for-any-image-containing-boxes-756c15d7ed26 , but don't know how to crop the table part in an image.

The image I used here:

now I want only this part like this:(manually cropped)

Thanks in advance!..

from detect a table part from entire image in python