As others have statement, table data is probably loaded dynamically by javascript.
- You can either search through
network
tab in developer tools and maybe find what request returns the data you need. Then instead of analyzing html of main document you will probably get some JSON from other URL with parameters. XML/HTML and other formats are possible too. If authorization is needed you probably have to recreate all http request headers too. - Or try integrating something like Selenium into your script - which will use real browser that executes js scripts. Its mainly used for testing but should also work for scrappingscraping data. There is probably also option of using some headless browsers along the way if opening a new window isn't welcome :) Apperently there is already library that integrates selenium with R - good luck :) Scraping with Selenium - R-bloggers