Some comments and questions, in no particular order.
a) JSPs don't access files (or do any kind of I/O), so I assume by "JSP and Java" you mean you have some backing beans and
servlets to accomplish those parts, structured in a MVC fashion.
b) By "table", do you mean a DB table, or a tabular GUI element in a web page?
c) By "I should be able to edit", do you mean manually, on a web page? If so, it seems easier if the user would just use a desktop spreadsheet app to do his edits, and then upload the resulting file. Why duplicate all that on a web page?