What is the name of the 'and' symbol on a keyboard?

It's called an ampersand. The origin of this term is interesting. Several centuries ago, children were taught their alphabets from flat slates with the letters printed on them called hornbooks. These books listed the 26 letters of the alphabet and at the end included the symbol for "and". This symbol was not part of the alphabet, but was by itself. The children were taught to recite the end of the alphabet "w . . . x . . . y . . . z . . .and per se, and" "And per se, and" became the Word "ampersand" since the children were never told what "and per se" meant and they thought it was part of the Word.