You should spend even more time with that link. Then you would notice that "ESC RS" is actually the ESC character (27 decimal, 0x1b hexadecimal) followed by the Record Separator character (30 decimal, 0x1e). From the linked table, you should be able to translate all printer control sequences into the values to send.

From the third column of the table, you can also see that the character 'A' is also hexadecimal 0x41 or decimal 65.

Most printers are using control codes outside the normal printable characters just because the control sequence must not interfere with the text you print. If the control code had been the text "ESC RS", how would you then get the printer to actually print "ESC RS", instead of treating it as a control code?