Hi Amin, it is a tipical "Sevillian sentence" it means literaly "What an art you have my soul", it is used when you sing or dance very well or you make a very funny joke or when you have created a very funny situation that make people laugh.
It is composed of two parts. First "My sould" means "My dear" sometimes people from Sevilla usually say "Mi arma" instead of "you" with family and friends. The word "arma" is a derivation of "alma" (soul, spirit) so "my soul" is "my dear".
And ¡Qué Arte tienes! is used in all Andalusia, not only in Sevilla, It is said in very funny situations for example, somebody tries to open a bottle and He is not able to do it, but He tryes and finally He break the bottle and all is a desaster, people start to laugh and they say ¡Qué arte tienes!. Somebody start to sing and He sings very well, people say ¡Qué arte tienes! ¡Ole! ¡Bravo!! You speak in a foreing language and you make a very funny mistake, and all the people laugh... they say you friendly ¡Qué arte tienes!