There are two ways to open a new document. Right click the tab and select "new" in the pop-up menu. Or you can double click Left Mouse Button on the blank area of Tab bar to create new document. Through the right-click menu you can also open folders where the documents exist.
 There are two ways to close the documents (workbooks, presentations). You can Close Tabs by clicking Middle Mouse Button or Double click Left Mouse Button on the Tab. It is available to close all documents and other documents. Select the function in the pop-up menu by right clicking the tab.