In this table, you can see that the proportion of people who use your company's product compared to the total market is fairly small, at only 13%.”
So Hannah is saying that when they talked to these people in their focus groups, all of them used a product, but not all of them used Vision Corporation's product.She points to a table and says that the proportion of people who use Vision corporation's product, compared to all the people who use all of the products, is fairly, or very, small at 13.
A “proportion” (proportion) is part of something, or a section.We could say a “segment” of something.
For example, I might ask you, “What proportion of the students in your English class are women?” meaning what percentage, what part of the class - how many.When Hannah says that the proportion, or smaller group of people who use Vision Corporation's product compared to the total market is fairly small, at only 13%, she means that only 13% of all the people who use the product buy it from Vision Corporation, and 13% is a small part of the entire market.
Hannah says that this means that the competitors have a big leg up on the market with over 85%.A “leg (leg) up” is an advantage, or something that helps someone.
You may have a leg up in getting a job because you know someone in the company - you have a good connection to the company.
In this case, because Vision Corporation has only 13% of the market share, its competitors must have 87%, which is a big advantage or “leg up” for these companies.