Do you get this message ? – “whatsapp doesn’t work on tablets”
Here is a workaround
TESTED ON GALAXY TAB 3
First you have to install Whatsapp on an working Android Phone (Ex: Galaxy S4)
After that, backup Whatsapp using App Backup and Restore app (it requires an SD card)
Transfer the .apk file created on the SD Card using an USB Cable or by transfering the SD Card.
Install the WhatsappBackup.apk
Add your phone number.
You will receive a SMS with a 6 digit code.
Whatsapp will try to detect the SMS but since you do not have a SIM Card after 5 minutes it will let you insert the code manualy.