Have a read on
www.sounddeadenershowdown.com before you embark on this project. What I learned there is that the "mat" products are vibration dampeners and that you only need to cover 30-40% of the meal area. The key is to add a layer of a product called mass loaded vinyl that actually blocks sound from passing through it.
This is yet another of those subjects on which we all have opinions and Im sure mine is different than a lot of folks here, but read that site and examine his data for yourself. I did and am very happy with the results.