The Fluance RT85 does not include a platter mat. The acrylic platter provided with the RT85 has superior vibration damping abilities, is resistant to static discharge, and will not damage your records. For these reasons, a platter mat is not needed!
The manual included with your turntable is the same manual included with all Reference series turntables. You will find a note under the platter mat showing the models that include it.
Below is an image of what's included with the RT85.