You can scan for duplicate contacts and then merge several duplicate contacts at the same time

Watch the walkthrough

How to scan for duplicate contacts

Steps

1. Select My Apps

2. Select Contacts

3. Select More Options

4. A dropdown menu appears

5. Select Merge Contacts

   Open

   

6. You arrive on the Merge Contacts page

7. Select Scan for duplicate contacts

   Open

   

8. Makerble detects sets of contacts with matching names and displays

   1. When the contact was created

   2. Who created the contact

9. Use the checkbox to select which sets of contacts you want to merge

10. Press Merge selected contacts

11. The merging will take place in the background