PDFs files can be very different one from another and contain links, buttons, form fields, audio, video, business logic, or they can be a simple collection of scanned images one for page even if they are a standard. Indeed the Portable Document Format, shortly PDF, are an open standard maintained by the International Organization for Standardization (ISO) .
The strategy to extract data from a PDF can differ accordingly with its
content, and not always the best way is to use an OCR; if the data is available directly inside it's better to avoid a level of data treatment that is not completely error free.
- If PDFs are created from a word processor document (Word,Latex...) you have good possibilities to successfully extract data without the need to recur to any OCR software. With some viewer you can select the table and export/save the selection at least in
txt format or in the
csv one; then you can import it in eXcel. A fast search on your preferred search engine will give you an updated list of
"open source" or "freeware" pdf tools export, or you can give a look to the wikipedia page about pdf software [1b].
There are some tools, even open source or freeware, created for this purpose and available for each operative system. With the Adobe program you can select the table and export directly  in
xlsx... Again a fast search on your preferred search engine will give you an updated list of
"open source" or "freeware" pdf viewers export table.
There are some internet site that offer for free this service, even if for bills I should not suggest you... included the google docs one .
- Last but not least if they are images or the other strategies failed you can use the OCR, setting a box to limit the OCR options. With FreeOCR ,for example, you can select the a box on which perform the OCR...
You can draw a box around part of the image using your mouse and then OCR the current page. This is handy if you just want to get the text from one region of the page.
If your OCR didn't support that feature, or it is not cosy to process many file at the same time, you can always recur to Imagemagick  or any other tool and extract a sub-image of the interesting area. Then you can give to your OCR only the selected sub-image, without header or useless area.
Ocr on the subimage -->
With Imagemagick convert you can do something similar to
convert -size 2480X3508 -depth 8 -extract 640x480+1280+960 file.pdf img.png
to convert a PDF file to a PNG one, with the A4 page size dimensions for 300 DPI and extract a box with the geometry parameters  of
640x480 starting from the point
Note that if manual scanned you will see different position of your region of interest for each page.