If you are using WhatsApp on your computer then you have to add every contact manually by going into emulator settings. Right? Similarly, if you use Viber on your PC, you need a contact list to see which friend has installed Viber.
In short, if use any Android emulator you have to enter contacts one by one. But there is an easy way to do that. For this instance, we will use Bluestacks as an example but the concept works for others as well.
Also read: Things you should know if you are using WhatsApp
The following video will demonstrate how to import contact list on WhatsApp in the latest version (2014) of Bluestacks.
You will need
1. Backup of your contacts in .vcf file
2. An Internet connection and a little patience
How to import contacts in .vcf file
Vcf short for vCard is a popular contact format. To import contacts from your mobile select contacts > export contacts > Phone.

Select import to phone instead of Gmail
If you are importing contacts from the Google contacts, you may not get contacts in the single list. To convert them into a single VCF file use the following command.
(Open command prompt and navigate to the directory where you have contact files and type in this command)
COPY *.vcf newfile.vcf
Now once you have .vcf file follow these step
Open bluestack and download Astro file manager.
C:\ProgramData\BlueStacks\UserData\SharedFolder. Make Sure to check show hidden files option.
Note: To make things simple I using this directory, but if you know your way around bluestacks than you can drop the vcf file anywhere you want, just make sure you can find it later on.