This can be interpreted in different ways: either she received a number of wicked traits from all the gods, or her 'box' contained not all evils but all good gifts for mankind (as some see it), or her casket contained all evils - although these are hardly gifts in the accepted sense.
Of course, it could also be said that since she was the archetypal woman, and therefore endowed with perfect feminine attributes, the gods gave her all gifts, that is, good characteristics, not evil ones. Certainly Milton saw her name thus. In his Paradise Lost he compares Eve to her, saying she is
More lovely than Pandora, whom the godsAllusively, too, her 'all-giving' could refer to the earth, from which she was made. There are in fact a number of parallels between Pandora and Eve (both, for a start, introduced evil into the world).
Endowed with all their gifts.
There was also another Pandora. She was the daughter of Deucalion and the mother of Graecus by Zeus. Graecus was said to have been the ancestor of the Greeks. Pandora's name has found a small but steady demand as a rather chic modern girl's name.