Yes, the Startech device is an industrial embedded server.
I am checking to make sure of the model of the ones that are in use now. But basically the devices that I am thinking of, all they do is take whatever comes in over the serial port and send it to the server ip and port you set it for.
If your program is a special program that requires using a COM port, it can be set up for that too. (for instance, if your scale has to communicate over COM3 in Windows).
I understand what you are saying. It's a fact though that every device that does this is a linux/bsd computer of some kind. It doesn't take much processing power but you need a complete tcp/ip stack inside. There are a bunch of manufacturers for these devices.
Also if we talk about scales that you would normally use in some kind of production or quality control, nowadays they commonly have an ethernet port either as standard or as an option. Still any real-time processing will be on-prem. Results might be sent to the cloud though for presentation and final storage.
That's what I'm seeing... can't imagine when we'd want a server "somewhere" storing a bunch of random scale data.