How Can i control the way the tabels in the admin panel build?
If you just want to style the D7 administrative theme (called "seven") differently, you can create a sub-theme of that theme and then customize. Docs are here: https://drupal.org/node/225125

Once you have a sub-theme, you can add you own css, templates, etc to change the way things look.

Because of the inheritance you get when sub-theming, you only have to add what you need to the new theme. For example, you could just have an .info file and custom css file.