how to convert datagridview data into table in word document using c# for windows application

It's not a question. 'Can anybody answer my question' does not tell us what you've tried, or what else you've done. You can use the tools for office[^] to write code that controls office, but your clients will need the tools ( and Office ) installed. Do you have an existing document you're already creating ? Do you have one that exists and you want to add to it ? None of this is clear.

You'll just iterate over your data and create a table and populate it, in code. You can buy third party libraries that integrate with word, and I believe they don't require office on the user machine.