There is no shame in being a slow learner, and just because a person is slow to learn in no way means that they cannot be a productive worker when put in the right situation. The best approach for a person who is looking for a job and is a slow learner is to find the jobs that are not dynamic in nature. Some good examples of jobs that are repetitive include typing and data entry, some construction jobs such as concrete work and roofing, and framing and foundation work, and there are a number of clerical jobs that require little decision making on the part of the employee that slow learners can thrive at after grasping the job.
Whatever the job is the main thing employees are looking for is someone who is dependable and can do the job on a daily basis. The main thing to remember once you land a job is to be honest with your supervisor and ask questions when you need answers, and show up on a daily basis ready and able to do the job. If you exhibit these qualities day in and day out, it matters not if you are a slow learner, your employer will consider you a valuable employee and you'll be able to work at that job as long as you like.