PDF and OCR
One alternative is to subject the .pdf image to OCR (optical character recognition) technology. This way, you can read the contents of the spreadsheet on a line-by-line basis.
The best time to turn the OCR option on is during the initial capture of the spreadsheet. However, even if the OCR option was not on when the spreadsheet was initially captured, it is always possible to go back and turn the OCR option on after the fact.
Again, OCR reads and records the spreadsheet, allowing you to identify the row identifiers. However, you still have lost the column names. Without the xlstab characters, it is very difficult to determine what the column names are.