The box content of the Samsung Galaxy Tab S6 contains the device, its charger, Data Cable and the S-Pen.
The good thing is that the user won't have to buy the S-Pen exclusively.
The user does have to buy the keyboard separately, however.
Check its unboxing-
Check Full Device Specifications Samsung Galaxy Tab S6
Yes, Samsung includes an S Pen with every purchase of the Galaxy Tab S6. But you will have to buy the keyboard separately if you want the full experience.
In the meantime, do not forget to find all the detailed specifications and other latest updates about the Galaxy Tab S6 here.