@Mia Chloe, the way you expressed it definitely suggests something else and that's how I understood it - but if you mean using VPN + Tor then it makes sense because it adds another level of protection so that your ISP doesn't see that you're using Tor, and at the same time, you can make it difficult for someone to get to your real IP address, even if he manages to "break" all the protection provided by Tor.
However, such a way of using the internet would very likely slow down surfing even more, given that for many people surfing with Tor is undesirable anyway due to the "speed" of surfing.