Hi Vadim,
Thank you for your interest in Essential PDF.
1) It is possible to import a large table from a dataset into a pdf document with column headers.
Here is a sample for your reference:
NorthWindReport.zip
and here is the code to import Data Table.
//Create a new PDF Table
ITable table = pdfDoc.CreateTable();
//Importing a DataTable
table.ImportDataTable(dsNorthWind.Tables[0],true);
2) Currently it is not possible to have row headers. However I will consult regarding this to the development team and send you an update as soon as possible.
Please let me know if you have any other questions.
Thanks,
Ajish.