SSMS 2012 mutiple query windows using same session
It is not possible to share a local temporary table between connections.

Local temporary tables are scoped to a single session, but global temporary tables are visible to any user and any connection after they are created, and are deleted when all users that are referencing the table disconnect from the instance of SQL Server.

Global temporary tables have two number signs (##) as the first characters of their names, for example:

CREATE TABLE ##GlobalTemp
(
    c1 integer NULL
);