It's so disappointing and disheartening that the basic table manners that most of us were taught perhaps with rhymes and poems when we were young do not have any impact in our daily lives today. One of the most important of these table manners is "do not talk while eating". Many of us probably think this etiquette is just to avoid being seen as an uncultured person especially outside our dining table, but it is far more than that, according to scientific research. I'll try to give a simple illustration with anatomical correlates which after reading, I hope will convince you by making you see reasons why you do your self more harm than good if you talk while eating.
Did you know that swallowing is a complicated process? You're surprised right? What happens behind your wide mouth is far more complicated than what you know as just gobbling a bite of pizza.
Imagine a large room (pharynx) with three openings or doors. One separately on one side (soft palate) and the other two lying side by side on the opposite side (epiglottis and esophageal opening). The first door leading to a room with transformer where electricity is generated (nasal cavity), the second opening having a passage leading to a room where wires are connected to receive electricity from the transformer (trachea leading to the lungs) and the third with a passage leading to a large tank for successive distribution (esophagus leading to stomach). Now assume that the large room (pharynx) is flooded by water (food). The first and second doors have to be locked swiftly, (closure of the trachea and nasal cavity by epiglottis and soft palate respectively) within seconds to prevent water from coming in contact with electricity, which we are aware of the havoc it can cause. This closure allows the water to efficiently flow down the third passage (esophagus) into the large tank (stomach). The process of talking largely depends on the frequent opening and closing of the second door (epiglottis). When you talk and eat, you unconsciously raise the risk of allowing flood (food) into the first and second room (nasal cavity and lungs), which may cause damage to the electricity supply and result in power outage.
The large room( pharynx) which subserves respiration and swallowing (depicted by the electricity and large tank respectively) must be quickly converted to attract that allows only swallowing, without compromising respiration. Can you now see that the whole process of swallowing is quite complicated?
I'm sure you know now that it's of more good to close you're mouth (stop talking)while eating and allow the complex process of swallowing to occur easily and efficiently.

I am committed to relentlessly serve humanity and pursue an optimal state of health for all humans. I am Babatunde Aina.