Build a React component that generates a table of numbers given the rows and columns.

Requirements:

1. Render two number inputs: one for rows and one for columns.
2. When values are entered, display a table with the specified number of rows and columns.
3. Each cell should display its row and column index (e.g., "R1C1").
4. Focus on functionality over styling.
5. The component should work out-of-the-box in a live React preview (e.g., CodeSandbox/Sandpack).