This is NOT a trick question…and many candidates appear bewildered and befuddled because silently they are thinking, “Well, what do you want to know?” or “Where do I begin?” or “Why don’t you just ask me specifically what you want to hear?” and so on. Let’s review what this question reveals. 
#1. Your Communication Style. If you are unable to clearly communicate about who you are, where you have been and your key skills and abilities in an effective manner; how can the interviewer expect you to clearly communicate about their products or services effectively once you are hired?.
#2. Organized Communication. When you can communicate in an organized, easy to follow manner, then this demonstrates your ability to communicate in that same capacity once you are hired.
#3. Confidence. An individual that can exhibit a confident demeanor while expressing their work history will make a more significant first impression.
#4. Extended Conversation. It allows for the interview to take on a greater depth, and allows you to expand on accomplishments that correspond with the job posting. In other words, you get to sell yourself.
Most candidates self-sabotage their ability for success in this all important area by saying too much or saying too little.
One of the most asked questions during the interview is “Tell me about yourself…”, and it is the single most requested question I receive when candidates are in the process of interviewing. So here is the formula:
Maintain a chronological format, keep it under two minutes, practice, practice, practice, and evolve shorter versions for career fairs and networking (a 60 second commercial).
Step 1: Start with your most recent position, state company name, your title, and job responsibility overview (one or two sentences) and a key accomplishment. (Be brief.) You goal is to generate interest and you can expand further into the interview.
Step 2: Next, take them back to the beginning of your career history (How I began my career…) and walk them forward (chronologically) back to your current position; (dates in this statement are not required) stating company name, position and job responsibility overviews, add a key accomplishment, here and there, that applies to the job posting.
MAKE CONNECTIONS FOR THE INTERVIEWER!
“I accomplished…..and noted that you were looking for someone with this particular skill, expertise, etc., or “This is where I gained the experience noted in your job posting.”
Step 3: Speak with confidence, enthusiasm, and practice so that you sound as though you actually did the work; avoid sounding as though you are uncertain as this will create a red flag for the interviewer.
Avoid talking about hobbies, family matters, where you were in kindergarten etc., keep it professional. If you left the workplace for personal reasons (stay at home mom, caretaker, etc.) state something like; “I made a personal decision to leave the workplace to attend to family matters ( to further my education, etc.) .” If you are confident about your choice; they will remain confident.
Good luck!