portfolio problem !

Hello there ! I am new at wordpress and also new at the forum! (this is my first post)

I am writing to make a question about this website :

http://www.musikey.gr/wordpress

It is the “xebax” theme.My question is about this place of the website :

http://musikey.gr/wordpress/artists/

When you enter the above link you should see a portfolio with many icons and something like a menu with this categories :

ALL CELEBRITIES DANCE DJS POP RNB ROCK SHOWS ΈΝΤΕΧΝΟ ΛΑΪΚΌ ΠΑΡΑΔΟΣΙΑΚΌ ΣΥΓΚΡΟΤΉΜΑΤΑ

All these categories are made by me except of the “all” category which was there by default.

THE PROBLEM is that there are almost 500 artists and you have to wait them to load.I want to make another category the default one.Or delete the “all” category, or make the all category show the posts sort by 20-20 !!!

HELP !!! 🙂