Edit the Receipt.html file, which should be in the "templates" folder. Insert tokens where you wish data to appear, much like editing a layout. There are numerous tokens you can insert for receipts, but you'll be most interested in <firstname>, <lastname>, <nickname>, <tablename and <seatnumber>. Complete instructions are in the included user manual, in section 35 "Exporting Data". Then look in Receipts, which is section 35.10.
You do need an html editor to edit the receipt template.
Regards
Stuart