The big question is: what are you going to do with all those records?
If you just want a backup, then keep the text file.
If you want to extract some information and create a report, then you could write an Excel macro to read the text file line by line, pull the information you want from each line, then put a summary in the spreadsheet at the end.
If you want to keep the data and have the ability to query it and create ad hoc reports, then you need Access or some other database. Excel can work as a database for relatively small amounts of data, but 14M is way above that limit. Yes, there is a learning curve to using Access, but if that's the right tool for the job, it's worth the effort.