Ct- abdominal wall: tiny fat-containing umbilical hernia. is this of concern? not much pain there (rarely some) and nothing can be seen or felt in that area?

Indications for operative repair of an umbilical hernia include pain, incarceration, strangulation, defect larger than 1cm, rupture. Operative repair of adult umbilical hernias is typically recommended by surgeons.

Radiologic tests need to be interpreted given the clinical situation that they were ordered in. Having said that, your description makes it sound as though it is not a worrisome finding. If you start to develop pain or other new symptoms, see your doctor.