What actually happens when I chew food?

Correct chewing can only take place if a “reasonable” – like in small - amount of food is taken in per mouthful, so as to leave enough room for the food to be spread out over as large an area as possible in the mouth. This will allow the saliva and the enzymes to mix in with the food and do their work in the best way.
Too little is better than too much!
Faulty or insufficient chewing or mastication will place an extra work-load on the stomach and other organs which can cause many ailments and illnesses.
You will soon understand the functions of Saliva as well. The reason for such thorough mastication of sugars and starches contained in the carbohydrates is that their digestion begins in the mouth. The saliva begins to turn the starches and sugars into maltose (malt sugar/glucose), a form of sugar that the blood will be very happy to receive.
Better chewing allows the taste buds in your tongue and your mouth to fully register the various flavors of the food, which will allow you to really enjoy your eating experience and make it more meaningful. And you will be more satisfied whilst eating less.
Once your tongue has been allowed to control the chewing process to its fullest, it will then move the food (now called “bolus”) to the back of your mouth to be swallowed.