Terminology can be confusing in regards to Servers. A Game Server being technically specific is a “Software Instance” of the server files (exe) running as a Service.
Physical server (bare metal) is the actual computer running an OS.
You can run multiple “Game Servers” on a single Physical Server… just as long as you have the resources and you configure each “Instance” to run as a service.
On a Windows server, physical box running Windows OS, You’d want to use software like Fire Daemon to define the instances as windows services.
Fire Daemon even allows you to allocate resources per instance. e.g. Cores, Ram, HDD etc.