You could check out the Azure Forms Recognizer. It's designed to do exactly this and make even training a custom model pretty easy. It's also pretty cheap (free up to 500 pages) so you can always do a quick experiment and see if it does what you need it to
https://docs.microsoft.com/en-us/azure/cognitive-services/fo...
One day at an antique shop, I came across a book from ~1910 which had hundreds of pages of annual reports from railroads with many metrics we'd expect to see in the 10-K reports public companies file.
The book was published annually, but had much of its data in tables with grouped headers and cells, which could make automated OCR-ing with a good (useful) end result challenging.
I think it'd be interesting to map out the Railroad consolidation, track all their financial metrics over time, and do some level of forensic accounting to see if/which companies probably had funny business going on.