Thanks for your inquiry.
We have already logged an investigation ticket as PDFNET-38999 in our issue tracking system, for existing table manipulations. As it seems very complicated to modify existing table inside PDF, so initially product team will investigate regarding manipulation of existing tables, created by Aspose.Pdf for .NET. I have associated the ticket ID with this forum thread as well, so that once we have some significant results, you can be notified. Please be patient and spare us little time.
We are sorry for the inconvenience.