There's more to experience when you log in!
Let me add a bit more detail to John's suggestion.
Remember that the Explorer Window, which I think John was referring to, holds two lists: Maps/Layers and Tables.
You can drag a layer from one map to another map inside the layer list. You drag it up or down and dump it into another map in the layer list. In this way, you can copy a layer from one map to another map including all the layer settings. You can't drag and dump a layer into a map window on the right.
If you drag a table from the table list and drop on top of a map in the layer list, the table will get opened in its own new map. You can also drag a table and drop it into a map window on the right. This will add the table as a new layer to that map. It will however not include any layer settings as a table by default doesn't have any layer settings.
A final note: If a table has a default theme, this will be applied to the layer if you add the table to an existing map no matter the way you add it to the map.