Yes, You can host multiple website inside a single server. On a dedicated server, The number of websites is not limited.
All you have to make sure is that your website(s) keep their resource usage well within the CPU/RAM/HDD limits of your server.
You can use Commercial panels like cPanel/Parallels to do that easily, Or free open-source panels like ISPconfig, to achieve this. If you are a technical person, You can simply install Apache/Nginx and make vHosts to host multiple websites.