Yes, you can use an Amazon Fire tablet as a Kindle. In fact, the Amazon Fire tablet comes with a Kindle app pre-installed, which allows you to access and read all of your Kindle books on the tablet.
To access the Kindle app on your Amazon Fire tablet, simply tap on the “Books” app on your home screen, and then tap on the “Kindle” icon. This will take you to your Kindle library, where you can view all of your purchased books and download them onto your device for offline reading.
Additionally, the Amazon Fire tablet also allows you to access other e-book services, such as the Barnes & Noble Nook app or the Google Play Books app, so you can read books from multiple sources on the same device.