Deploy Unity 3D Project to Samsung Galaxy Tab

Install the drivers

Install the Samsung Kies software
It can be downloaded from http://www.samsung.com/ie/support/usefulsoftware/KIES/

Enable Developer Options on the Tablet

On the tablet
Go to Settings -> General -> Left hand panel, scroll down to About device.
In the About device main panel, scroll down to Build number and tap it 7 times.
Quit the settings application.
Go to Settings -> General -> Left hand panel, scroll down to Developer options.
Tab the Enable USB debugging checkbox

Configure the Build Settings

In Unity go to File -> Build Settings...
In the Platform panel click Android and then click the Switch Platform button
Click on Add Current to add your scene to the android package. If you have multiple scenes in the game, make sure to add them all and make sure that they are in the correct order

Build the Game and Deploy to the Tablet

Then in Unity do File -> Build and Run

The first time you perform a build and run, you should get a notification on the tablet to allow the application to get pushed to the tablet. Allow this. Pushing the game to the device might fail, if it does click Build and Run again in Unity. It should start the game on the tablet.