It definitely won't work. You need RAM specifically made for laptops or similar machines.
Laptops use SO-DIMMS, which are compact and much, much smaller than the desktop DIMMs and besides the pin-outs are different and they wouldn't fit.
That said adding more or RAM to the laptop will surely help your games. You won't see the affects of a faster or better video card which you can't usually do in a laptop, but the additional RAM will relieve the pressure on the system overall as it seeks out resources to run your programs.
With this in mind, you need to find DIMMs that exceed the size you already have. You currently have 8 GB installed. If you were to install 2 x 8 GB DIMMS giving you 16 GB that's a good deal. Just remember you need to match the speed, refresh rate, and other specs required by your machine to ensure you have purchased the proper RAM. Putting in slower RAM will cause the system to operate worse even with more memory, and having RAM that more than exceeds the speed may not be of any benefit and a waste of money.
I recommend going to the manufacturer's website and looking at the specs and upgrades available for the machine. You don't need to purchase the RAM directly from them, especially if the price is much higher than the market, but instead use this resource to determine what you need to make your machine run better.
Hope this helps.