I thought about using labels but I'd need to scroll them horizontally when I do it to the webview and I don't know how to implement it. Not to mention that the webview columns automatically adjust their width.
There are some coding examples on the Net, if you search for 'html fixed table header', still, what I usually do in large tables, is to repeat their headers every some fixed number of rows,with a bold and some other color formatting, in order that the user to always see the column names, without me having to worry about setting the first row fixed. Just a thought.