CSV is an old & very popular format for storing tabular data. It has been used in the desktop as well as mainframe. It is a simple & compact format that works really well for tabular data and so is still in use today.
HTML is the language of the internet. It is what creates HTML pages (even this one). In the old days, HTML used to be static with some JavaScript added into the mix for dynamic behavior and effects. Then HTML was served dynamically from the server side with the advent of server side programming languages such as PERL, PHP, ASP. And now there is a new trend where HTML is again being served as static resources with JSON (from REST web services) and JavaScript making it dynamic.
[ { "name": "Robin Hood", "department": "Sales", "salary": 200 } ]
[ { "column 1": "Name", "column 2": "Department", "column 3": "Salary" }, { "column 1": "Robin Hood", "column 2": "Sales", "column 3": 200 } ]