To import contacts from an Excel file to Outlook, you first need to open the workbook sheet containing the contacts you want to save in the e-mail manager. When you have it open, go to File > Save As. You will see the following window:

Browse to the location where you want to save the file. Once there, click on the tab that lets you select the type of file to save the book in:

From all the available ones, click on CSV:

Click on the Save button. You will get the following message on the screen (do not worry, this is a limitation that only affects CSV files; your original workbook will remain the same):

Click OK and you will get the new file. Now, the original Excel file will be closed, and the CSV file will be opened. Close it yourself and open Outlook. At the top of the mail manager window, select File:

Click on Open and Export:

Then, click on Import / Export:

In the window that appears, select Import from another program or file and click on Next:

Then, select Comma Separated Values, and click Next:

Browse for the CSV file that you want to import by clicking on Browse and click Next:

The Contacts value should be selected by default. If this is not the case, scroll up or down until you find it and select it. Once you have it, click Next:

Make sure that the box next to Import filename.csv is checked:

Now, before finishing the process, we have to match the CSV file columns to the Outlook contact fields. To do so, click on the Assign custom fields button:

Matching fields will be matched automatically, but you may have to match some manually. Click on Finish and the process will be complete:

The process seems a bit difficult, but if you follow the steps described below, you will have no problems.