So I tried iReader but it is not very good in opening large CHM files (I get 404 file not found error). Calibre was also not too helpful since conversion to epub/pdf, since the converted files were not readable (contained garbled text). I did try several files.
Finally I figured out a way around it. There is a simple windows program called chmdecoder (http://www.gridinsoft.com/chm.php). It converts CHM files into HTML file format. I transferred the files to edge. However, you need the Astro file manager app in your edge to open the local HTML files (when prompted I used Dolphin browser).

I tried a few books and it works well.