Usage of the word "memory"

Solution 1:

If you are using memory in the sense of recollection, then yes.

However, I would suggest that you word the sentence this way:

I have a clear memory of putting my key on the table.

Meaning that you remember, or recollect, the action clearly.

Solution 2:

there are two memories: countable - something that you remember (childhood memories) and the other is uncountable - the ability to remember things (memory for names) – Unreason

(posted as a comment on this answer)

"A good memory" is only used in the second sense. Your example is using the first sense , so 'a definite memory' or, as Gnawme says, ' a clear memory' would be usual.