@Renanholanda

"cracking a wep network" using linux is not a difficult task. Learning to do it on your tablet however, adds layers of complication.

I would suggest installing one of the linux distros like Ubuntu and going to this site and reading the tutorials.

Once you have the aircrack suite down, and are familiar with wireless packet capturing, you can start worrying about buying hardware or using a multitude of other tools, including your tablet. Please feel free to PM me if you have specific questions, but know that there is a learning curve that you are expected to pass by yourself. Everything you need to know is freely available and well documented.

Hope this helps