Calibre and online sites can convert from PDF to Epub usually lose most of the format. I tried PDFElements, with similarly poor results.
Is there any service/app that actually works and converts a PDF to Epub in a way that resembles closely the original?
The official Adobe online converter always gave me the best results, I used it for invoices with tables and odd formatting all over. They have limits on free, but it should handle a small book. Not direct to epub, however.