The best way to do this is to place a router between you and the internet. I have a wireless router connected to my cable modem, and all of my computers at home connect to the router. The router has a built-in firewall that by default allows outgoing traffic (all computers can access the internet) but disallows all incoming traffic (noone outside my home network can see any of my computers). I run Tomcat and Apache on some of my computers and can access them from others, such as from my tablet while I'm watching TV.
Notice that there is no setup or configuration whatsoever with Tomcat.
Here are the steps you can follow:-
1. Connect your system through a network device
2. Find out the Ip of your system where tomcat is hosted
a. Run the command ipconfig(windows) or Ifconfig (linux) in command prompt . it display the Ip address of the system
3. once you know the IP address, browse http://ip:8080 from your tablet or handheld device