Good Day Benneth Obilor re: A tool to capture all my posts and comments in a tabular form: The steps to archive and download your own FB posts are readily available online and in FB help pages. Once downloaded you may need to wrangle the data into a format you need, but that is another query. Caution: although you may be able to legitimately scrape public profile data and some posts for other users, there is no legitimate method to download an archive of another person's Facebook data and little chance of you being able to legitimately use such data in your research.
Here is one of many online guides for your own data: