(define csv-file
  "C1, C2, C3, C4, C5
    1,  5,  9, 13, 17
    2,  6, 10, 14, 18
    3,  7, 11, 15, 19
    4,  8, 12, 16, 20")

(display (all-rows (open-input-string csv-file)))