I have bank statements that I down load from the banks in PDF form. The conversion to excel on a line by line basis breaks some of the description part into several cells. I suspect it is based on the number of spaces between words in the description. Is there a setting that I can modify to prevent this breaking up the entire description into more than one cell?
No, and it's much much more complex than that. There's basically no such thing as spaces between words in a PDF file. Each word (actually, each character) exists on its own and the application does its best combining them to meaningful pieces of text when it exports them to another format. As you can imagine, that is an extremely complicated task and many times the results won't be perfect.
However, most banks nowadays offer direct Excel (or CSV) download options. Check if you bank has this feature, as it's much preferable to exporting a PDF to these formats, as you've seen.