Can you use that URL in the browser (
http://192.168.1.105:8080/) on your tablet? If you cannot, then something basic is broken: either your tablet is not connecting to your local WIFI LAN or something (a firewall) is blocking it from accessing the calibre content server on your machine. Notes:
- your tablet must be connected to your home WIFI, not to some telephone data connection, and it must have an IP address that begins with 192.168.1. I don't know what you mean by "connects as a guest".
- your PC must still have that IP address (192.168.1.105). Check it, because the address can sometimes change. Best would be to tell your router to always give the same IP address to your PC. This option will be somewhere in the router's configuration options.
- The firewall on your PC must permit incoming connections to calibre.
Do I understand correctly that you have a netbook in addition to the PC and the tablet? If so, can the netbook see the content server using the above URL?
If the tablet can connect with the browser, then try the URL
http://192.168.1.105:8080/opds in aldiko.