Is a half banana, a salmon and avacodo/tomatoe/onion/spinach leave/parsley/pepper sandwich on whole wheat with water to drink a human healthy lunch?

Sounds ok: The sandwich sounds ok, especially if it has no sauce/spread, or just a small amount. Healthiness of a sandwich can also depend on how big a sandwich it is, and on how safe the ingredients are (cooked foods are safer because cooking decreases food bacteria).

Healthy lunch.: Sounds good for a human, and perhaps even for other species as well. Protein. Healthy fats. Fiber. Nice.