The Store Editor Type and Catalog Manager Table are, for the most part, the same thing with different names.

A Type is created in the Store Editor to define the properties that will be associated for items of that Type. The Editor provides several built-in types and also provides the ability to create custom types. When creating an item in the Editor you must specify the Type it belongs to.

A Table is created in the Catalog Manager and defines the fields associated for items of that Table. The Catalog Manager provides a "Default-table" for you to use and also provides the ability to create custom Tables. All items that are created in the Catalog Manager must belong to a specific Table. You can move items between Tables.

The "item." Custom Type in the Store Editor is the same as the "Default-table" in the Catalog Manager. The items of the "item." Type in the Editor and the items in the "Default-table" in the Catalog Manager are virtually identical. If you delete an item in the Editor it will delete the item in the Catalog Manager.