Selecting the data source text file
On the Import tab, select the Text file option in the Data source type section.
Select the file that contains the structures from the Data source drop-down list , or select in the list to search for a text file. Then select the separator that is used in the text file from the Separator drop-down list.
The structure of the file is shown in the import table when you click Mappings column, you can map the columns of the source text file to the columns of the selected dimension.
beneath the import table. When you double-click a cell in theTo view the data that will be imported from the text file, click Data beneath the import table.