The Action seems to be the custom event setup to capture a specific event on the website. Since this is a custom setup by the company, more information should be available by the developer or the analyst who had this done.
If you are trying to answer for % of people, you should look at unique visitors metric. So if you want to see the % of people who went to Training, it would be 59145 / 493238, i.e. 11.99%
If you are question is regarding how many times a specific 'Action' took place (assuming it is counting the button clicks on the Action Buttons), then you would be using the Action column values.