How to combine multiple .vcf files into one
If you have your contacts exported into .vcf files, they can easily be imported into for example iCloud, Google or your email program. However, if you have a couple of hundreds or thousands of contacts, and equally amount of .vcf files it will be very inefficient to import each contact one by one.
A solution is to combine all contacts into one single .vcf file. By importing the combined .vcf file all your contacts are imported at once.
To combine all .vcf files into a single one can easily be done using a Windows command prompt (cmd).
cd directory-path-where-your-vcf-files-are-located
copy *.vcf allcontacts.vcf
Now import the file allcontacts.vcf into iCloud or similar.