Self evaluation is a proxy for self reflection. Broadly speaking, teams of people work well when each team member knows who they are, what they're capable of and what to contribute and when. Assuming you employer is acting in good faith, then the question here isn't: "Are they trying to get me." but "Do I understand my skills and my contributions and can I grow as a professional?"
Broadly speaking what the questions do, is try to gauge your disposition as a team member. Get a sense of where you are and what your skills are. No one can be good at everything, so it helps to lay out what you're good at and if your employer agrees, it helps them better define your role and tasks. It also Controls expectations.
To use a tech reference. If someone asked me what I was weak at I would say
Well, I'm not a front end developer. I'm not comfortable with JS technologies I am a weak front end developer. I am very strong with C# and SQL."
and then I could follow up with...
"Depending on what the team needs, I'm more than happy to be stronger at front end, however many of my current tasks are SQL / C#. So those are the places where I have developed a lot of expertise. If the team needs me to transition to JS tech, I can do that. There will be growing pains, but it's absolutely doable and of course, I would need my tasks to either change or include the new tech so I can keep my new skills fresh."
Final note:
What are your strong and weak points?
Between 1 and 10, how do you evaluate your communication skills?
Do you think you are good at managing people? Give a score 1-10 etc.
These are not "gotcha questions", these are simple questions about your confidence in your abilities.