This question is an exact duplicate of:
As a moderator I can see deleted posts in a profile, but -- without visiting each one -- I can't see when they were deleted.
This came up because I came across a user with a small number of posts, all deleted, and I wanted to know if I was looking at a rage-quit. If deletions caused entries in the "activity" tab on a profile this would be easy to check; instead I had to visit each post to see what was going on. But even beyond suspected rage-quits, it seems like this would be a helpful addition to understanding a user's activity -- for example, in detecting a pattern of deleting questions as soon as an answer comes in.
Since deletions that produce reputation changes have to be tracked on the "reputation" tab, it seems like deletions already produce some per-user record-keeping. Is it feasible to add information about self-deletions to the record of the user doing the deletion?