React Table is a collection of hooks for building powerful tables and datagrid experiences. These hooks are lightweight, composable, and ultra-extensible, but do not render any markup or styles for you. This effectively means that React Table is a "headless" UI library
React Table is a headless utility, which means out of the box, it doesn't render or supply any actual UI elements. You are in charge of utilizing the state and callbacks of the hooks provided by this library to render your own table markup. Read this article to understand why React Table is built this way. If you don't want to, then here's a quick explanation of why headless UI is important:
By acting as an ultra-smart table utility, React Table opens up the possibility for your tables to integrate into any existing theme, UI library or existing table markup. This also means that if you don't have an existing table component or table styles, React Table will help you learn to build the table markup and styles required to display great tables.