A lot of people I met usually don't have any table manners. Having a good manners on table will give you edge over the others. You stand out and make a good impression on everyone especially to your partners, bosses and to totally strangers.
In my current work at Talavera Group of Companies, employees do not practice table manners or don't have any idea about it.They usually chew with their mouth open, talk when their mouth is full, they are not sitting straight, placing elbow on the table and a lot more.
The benefits of such manners is discussed in this link.You may visit www.mannersinternational.com containing good resources for manners and etiquette.