Your Fabia is well within the threshold of being able to use E10 (regular unleaded) fuel. It'll run perfectly well on it and shouldn't cause any adverse issues in the long run. However, it can be beneficial to occasionally switch to E5 premium unleaded, primarily because the detergents in it can help reduce carbon build up in the fuel system. This is particularly beneficial if you do lots of short journeys where the engine doesn't get hot enough to burn off these deposits.