Tamten is masculine and so is man. The neuter form is "tamto", e.g. tamto dziecko (that child)
There's exceptions. It's always masculine if you're talking about a man and vice versa.
Native English speakers: do you really say "THAT apple is tasty" and not "This apple is tasty"?
Not a native, but I'm pretty sure they say both, depending what they mean. If the apple is close or somewhere further.
If it is in my hand i would say "this apple", if I am pointing to it I might say either (this/that), but if it has been mentioned already in the conversation I would always use either "that" or "it". Example: "What do you think of this apple?" "That apple is tasty" or "It is tasty", but replying with "This apple is tasty" would sound weird to me unless i was pointing to it.