Every component table contains five standard columns. These are explained on the page for Matching and Storing Device Attributes.
Each component table is joined to the system table by component.system_id = system.id and uses "on delete cascade". Hence if you delete the entry in the system table for a device, the joined component tables will also have the data for this device deleted.
Other attributes are also stored, depending on the component in question.
The following are the tables for the relevant attributes - attachment, bios, disk, dns, file, ip, log, memory, module, monitor, motherboard, netstat, network, nmap, optical, pagefile, partition, print_queue, processor, route, san, scsi, server, server_item, service, share, software, software_key, sound, task, user, user_group, variable, video, vm, windows.
The schema for these tables can be view in the application if you have the admin role. Go to menu -> Admin -> Database -> List Tables and then click the View button for any table.