In order to use this feature, you'll need to make sure two things.
First Both Samsung devices you're using need to be on the same wifi network
Ans second you'll want to make sure "Call & text on other devices" is enabled.
To do this: Swipe down your notification shade and tap on the gear settings icon on your phone> next scroll down and tap on "Advanced settings"> next toggle on "call & text on other devices".
Make sure this feature is turned on on your galaxy tablet as well. Once this is on; both devices should see each other and will ask of you would like to pair them.
