So if a company asks the question, "What can you bring to the table if I hire you?" They are basically trying to asses whether you fill the needs they have when they posted the job. You see a company posts a job because they have a problem they need a certain skill set and a certain amount of support provided to them in this role or in this position. And it's listed in the job description exactly what roles and what responsibilities they need full filled.
So your job during the job interview is to convince them that you bring those skills that they need, you can full fill those roles and responsibilities that are listed in the job description. It's just that simple. So basically, if you are asked the question, "What can you do for the company?" Take a look at the job description, and highlight 3 to 4 things that are in the job description and how your background lines up to those skills. For instance, if they need someone who can teach their customers, you can talk about your experience in customer service or your experience in teaching or anything that is related to it.