The Copy as Tab-separated Text command is enabled only when the selection is a range of cells in the Table Display of XML Grid View and JSON Grid View. It can be used to copy table-like data in tabular form and to spreadsheet applications.
The screenshots below show how two rows in Table Display are copied as tab-separated text.
The next two screenshots below show the data pasted as tab-separated text into a Microsoft Excel document and a Notepad document, respectively
Notice that while Excel (screenshot above) automatically formats each cell on the basis of the text's lexical form, Notepad (screenshot below) pastes all cell text as strings.