Ecclesiastes 9:5

[Bucky Ball]

It means the memory OF THEM (eorum) has been given/delivered/transitioned to oblivion.

The Jews did not believe in an afterlife / "going to heaven".  
All dead souls went to Sheol.
Later that changed, but even then, the sect that believed in "resurrection of the dead" thought that happened at the end of time.
Meanwhile, the dead were dead.

Psalm 39 :
"Turn your gaze away from me, that I may smile again,
before I depart, and am no more"

Psalm 115 :
The dead do not praise the Lord,
nor do any that go down into silence".

Psalm 6 : 
"For in death there is no remembrance of you, in Sheol, who can give you praise ?"