Yeah, if you work for a large company generally a network administrator will have a number of people working underneath them doing various tasks, and you merely coordinate them so to speak. Obviously a network admin is such a broad term, but a LAN network admin will generally:
-assess needs of the company and acquire the proper hardware/software that the company needs. This includes PC, network equipment, periphirals like printers and such, and software such as operating system and office etc.
-setup and maintain these services, which basically means setting up all the computers to work under the network, make sure they're working properly, and keep them up and running. This means you have to know how to troubleshoot hardware problems, software problems, network problems. You need to be able to make cat5e cables rather readily.
-data backup, most corporate networks will use a client server where all info is stored so it's basically your responsibility to ensure minimal downtime and make regular data backups and whatnot
-possibly also experimenting with cracking/hacking into the network through external means, to find exploits or security holes in the network so they can be fixed
So basically I guess you can summarize it as basic maintenence and security procedures. It's really a few hundred smaller tasks if you want to get technical