salver: [17] The word salver recalls the ancient practice of paranoid monarchs employing a special servant to taste their food before it was committed to the royal mouth, in case it was poisoned. The Spanish term for this was salva, a derivative of the verb salvar ‘save’, hence ‘make safe, try something out to make sure it is safe’, which in turn was descended from Latin salvāre ‘save’ (source of English save). By extension the Spanish noun came to be used for a tray on which the tested food was presented to the king, and it passed into French as salve. When English adopted it, the ending -er was added, perhaps on the model of platter. => save
salver (n.)
1660s, "tray," formed in English on the model of platter, etc., from French salve "tray used for presenting objects to the king" (17c.), from Spanish salva "a testing of food or drink" to test for poison (a procedure known as pre-gustation), hence "tray on which food was placed to show it was safe to eat," from salvar "to save, render safe," from Late Latin salvare (see save (v.)).