For joomla1.0

Tab Show requires you to setup 15 new module positions. For more info read template-helt.txt which is included on the zip you have purchased.

For joomla1.5

For tab modules just choose in module positions for the modules you want _tab1, _tab2 till _tab15. Those tabs are included in template and you don't have to install any module

To change the names of those modules you can do it in Extensions- Template Manager. Select the template, click edit and change the names of tabs there.