The project portfolio includes additional relevant information that did not fit into the CV. We recommend describing on average three selected projects of either high complexity or spectacular successes. A well-structured add-on furthermore sets you aside as a motivated, well-prepared candidate, communicates your work style and train of thought. It shows your reasoning abilities, analytical skills and business acumen. The formatting should be coherent with your CV.
This kind of document is usually prepared by lawyers in law firms to portray their expertise: Transaction List.