Would it perhaps be beneficial to talk about your interests or something that sets you apart from other candidates? Or would this be a bad idea?
If you feel you need to share more than what your CV says (when asked "Tell me about yourself"), be more on point and have a take-home message. Interviewers need to see someone who is astute and succinct (i.e., convey much with less words - which anyone can tell by my verbose posts, I'm still working on this goal).
If you want to be memorable (and you think your essays didn't achieve that goal), come up with your target message now (which it seems is the goal of this thread, so bravo). Like for me, it was to convey I was team player, so I may have said something upbeat, like "I am enthusiastic, hard-working, committed, and my colleagues/supervisors have consistently shared that they enjoyed working with me. And I enjoy contributing to a pleasant environment, no matter the gravity of the work."
And when it came to MORE personable qualities, I had my blanket statements there, too. For example:
"I'm family-oriented." (could mean I'm close with my adult siblings, or I have four kids...both are true...but I'm not sharing any of this on an interview; this conveys appeal towards my familial relationships - not necessary, but interesting)
"I'm detail-oriented." (could mean I could be obsessive, but usually no detail gets left behind; conveys how I am as a worker)
"I'm a team player." (could mean I'll go out of my way to get along...which I do; conveys my interpersonal functioning above & beyond patient interactions)
So...you get the picture. All of what you say about yourself should be backed up by your application (rec letters, essays, CV). Just be authentic.
Edit: For some reason, I was thinking internship interviews (at that point, most doctoral candidates know how to answer this question to present themselves in a favorable way). But, my points still stand for doctoral interviews, too.