A single-table layout is a standard list project with a single table object. This option is active for all projects by default. If you want to create a project which uses multiple tables, then use the options "multi table layout" or "fill several tables successively".
Note: In most cases, one table object will be sufficient, even for complex projects. The table layout can be controlled dynamically by using line definitions and the dynamic placement of tables (i.e. change a tables layout depending on the current page). Additional info can be found in the NotesToPaper Designer help file.