And then stack area will begin from xxxxh+1 actually.

Exactly, Although your stack storage starts at 08h by default. but your Stack Pointer i.e. SP holds value 07h when your 8052 is booted/started. The point is that Every time you or your program put something onto stack 8052 will first increament your stack pointer and then will save the content at incremented location.

Regards,
Prahlad Purohit