You need to have at least the same number of columns and each column has to be defined in exactly the same way, i.e. a varchar column can't be inserted into an int column.
For bulk transfer, check the documentation for the SQL implementation you're using. There are often tools available to bulk transfer data from one table to another. For SqlServer 2005, for example, you could use the SQL Server Import and Export Wizard. Right-click on the database you're trying to move data around in and click Export to access it.