For more, see Layer Tools
To Activate: Tools menu
Add the content of one layer to another.
To Use:
Activate Append Layer tool.
Select Target layer, or layer to which information will be added, from drop down list.
Select Next.
Select Source Layer, or layer from which information is to be appended from. Select Next.
In the dialog that opens, match fields from the source layer to the target layer. Select Next.
In the dialog that follows, check or un-check the Auto Increment MUID box.
Select Append Layer to complete the process.