If you own an iPhone as well then you can make and receive calls on the iPad using the cellular connection of the phone.

On the iPhone, open the Settings app, select Phone and select Calls on Other Devices. Make sure Allow Calls on Other Devices is enabled. You can then toggle specific devices on or off – choose your iPad from this list to enable it. You can also use this setting to make calls from a Mac or another iOS device.

Follow the same steps on the iPad. As long as the devices are near each other and connected to the same Wi-Fi network, you’ll be able to start calls from the iPad as well as receive them.