Original sentence: However, these perception of "rudeness" have in modern time started to fade away.The traditional perception is that the right hand should hold the chopsticks and the left hand either hold down the bowl on the table or pick it up so that it is near the mouth, and holding the chopsticks with the left hand or eating with only one hand on the table (even in some exceptional cases when one may eat without a hand used to hold or pick up the bowl) has traditionally been perceived as rude behaviour
Edited sentence: However, these prejudices of "rudeness" have in modern time started to fade away.The traditional perception is that the right hand should hold the chopsticks and the left hand either hold down the bowl on the table or pick it up so that it is near the mouth, and holding the chopsticks with the left hand or eating with only one hand on the table (even in some exceptional cases when one may eat without a hand used to hold or pick up the bowl) has traditionally been perceived as "rude" behaviour