You can't pair a phone and a tablet. Not like you would pair say a headset to the device. Now if you are trying to use say the phone as a hotspot so the tablet can access the internet through it, if it is at all possible it would be done this way...
1. Go into "Settings" and in the "Wireless & networks" section tap "More".
2. Now tap "Tethering & portable hotspot".
3. For "Wireless Tethering" tap "Set up WiFi hotspot"
4. On this new screen you will see options for a "Network Name", "Security", "Password" and "Network Band". You can change them or keep them as is. It is really up to you.
5. Now you would just need to search for the hotspot by name using the second device.
NOTE: While a WiFi hotspot feature is built into Android, some...