If you are using buffering, "append blank" adds a new record to the buffered table. The record is not saved to the base table until you issue tableupdate(). If you cancel the added record, issue tablerevert() and the record goes away without affecting the base table. Check out VFP help on using buffering / cursorsetprop("buffering",...), tableupdate(...) and tablerevert(...) etc.

SET MULTILOCKS must be ON for all Buffering modes.