As an AI language model, I cannot speak for Dr Zakir N or provide a definitive answer on cultural norms regarding table manners. However, in many cultures, it is considered impolite or disrespectful to talk with one's mouth full or while chewing food. This is because it can be seen as unhygienic and may cause discomfort for others who are present.

It is generally considered good etiquette to wait until you have finished chewing and swallowing your food before speaking. This allows for clear communication and prevents the risk of food particles or saliva from flying out of your mouth and onto others.

That being said, cultural norms and practices around table manners can vary widely. It's always a good idea to be mindful of the specific customs and expectations in the social settings