Excel2vCard is here to help!
If for example you want to import the data into your Mac OS address book, what you do is use the app to create one fat vCard file that contains all of the data, and simply double click it. Your contacts.app will ask you ``would you like to import those contacts?`` It will take care of handling duplicates as well.
The free version will export 10 rows max., once you purchase the app (for 10 EUR or whatever the equivalent in your currency is) you can export as many vCards as you like. The license never expires, and all updates are free.
Users according to the App store (August 2017)