Is "Health" ever utilized as a rejoinder or a blessing-directive?

When a person in the vicinity sneezes, a German says, "health!" (gesundheit); when a Mexican (or all Spanish-speaking?) wait[er,ress] delivers food to a table, [s]he says, "health!" (salud). In what circumstance does an English speaker say, "health"? Ever?

Solution 1:

The simple answer is that the only circumstances in which "health" is normally said as a one-word statement are those in which the generic uncountable noun "health" is the answer to a question. E.g.

Questioner: What is the most important thing: money, or health?
Answerer: Health.

In English we don't say "Health!" in the circumstances you describe.

When someone sneezes, a standard response is "Bless you" (less commonly "God bless you", which is in a more formal register) or "Gesundheit".

When someone delivers a meal to your table, it's often accompanied by an imperative such as "Enjoy [your meal]!" or the salutation "Bon appetit!" which Merriam-Webster defines (with a diacritic):

bon appétit French phrase
: good appetite : enjoy your meal

In English we simply never use the one-word statement "Health" as a salutation, blessing or wish. If used as a salutation, blessing or invocation, it would typically include a determiner to provide context; e.g.:

"[To] your health!" (e.g. as an informal toast, often accompanied by the bringing together of drinking vessels to create a pleasing "clink" kind of sound)

"[To] the health of (insert the name of someone important)!" (a more formal toast, to which a standard response is to raise one's glass, repeat the invocation, then take a drink).