Im using prawn to create pdfs that contain much data in table format and some lists. The problem with the lists is that Im just using text as lists because there is no semantic
Prawn was a good PDF library but the problem is its own view system. There is Prawn-format but is not maintained anymore.
I suggest to use WickedPDF, it allows you to include simple ERB code in your PDF.
Using Prawn: another dirty and ugly solution is a two column table without border, first column contains list-bullet, second column text:
table([ ["•", "First Element"],
["•", "Second Element"],
["•", "Third Element"] ])