A new one that I came accross today. If you are importing data into a table, the Table Name is identical to that specified in the 'Object Type' section of the SQL editor. If the Table name includes spaces then the table name should be contained within square brackets. The space is NOT represented using an underscore.

For instance to add data to the Runoff Surface table the SQL table reference is:-

[Runoff Surface] NOT Runoff_Surface