The job interview is your time to shine. Someone is interested in hearing your story. Don't clam up. Everyone has varying degrees of shyness, but you need to talk about your employment experiences concisely and in an interesting way.
Conversely, don't ramble, even when there's a pause in the conversation. If you ramble, you might tell the interviewer something you don't want them to hear. Just give enough detail to answer the question. Rambling also raises doubts about your ability to organize information [source: U.S. News].
Sometimes interviewers will be silent on purpose. There's nothing more uncomfortable than dead air. As a result, the interviewee starts talking because they figure there's something wrong with the answer they have just given. If the interviewer gives you the silent treatment after you answered a question, shut your pie hole and show confidence in your previous answer. If the interviewer is still silent, ask a question such as "Did I answer your question?" or "Would you like me tell you more?" [source: Adamchik].