Does JavaScript have a Map literal notation?

No, ES6 does not have a literal notation for Maps or Sets.

You will have to use their constructors, passing an iterable (typically an array literal):

var map = new Map([["foo", "Foo"], ["bar", "Bar"], …]);

var set = new Set(["Foo", "Bar", …]);

There are some proposals to add new literal syntax to the language, but none made it into ES6 (and I’m personally not confident they will make it into any future version).