"Mesa" in Spanish means "table." Two tables figure in the coat-of-arms above.
There is more than one possibility how this name originated. It depends on what part of Spain the family came from. There are different Mesa families scattered throughout Spain, and they didn't all come up with the last name Mesa in the same way.
For some, the family took as their last name the name of a village or town or area.
Even the spelling can differ. Remember that for people from southern Spain, and for Spanish-speakers in the Americas, Z and S sound the same. Zaragoza is pronounced Saragosa. Perez is pronounced Peres. So some people spell it Meza, but for many of them it sounds exactly the same as Mesa.
That's why in the Marianas, where the Spanish Z and S sounded exactly the same, in the old records, sometimes it was spelled Mesa, sometimes Meza, just as we see in Blas and Blaz.
Sometimes it was de Mesa, "de" meaning "of." Many times, however, the "de" wasn't used and it was totally dopped by the time the Americans took over Guam.
Appears in the 1727 Census
The Mesas in the Marianas go back a long time. Jacinto de Mesa appears in the list of Spanish soldiers on Guam in 1727. As we always say, this doesn't mean he was definitely from Spain. He could have been; but he could also have been from Latin America (a Mexican, Peruvian, Chilean) though more than likely, had he come from Latin America, he could have been a pure-blooded Spaniard born in Latin America or one with mixed blood (Spanish and something else).
Jacinto was married to Maria de Leon Guerrero.
In the 1758 Census, there is still only one Mesa listed, again in the list of Spanish soldiers.
He was Manuel Gonzalez de Mesa, married to Margarita de la Vega. We cannot be sure if there is any link whatsoever between him and the earlier Jacinto, but there could have been.
By the 1897 Census, there were many Mesas, mostly in Hagåtña, but some had moved down to Hågat by then.