The dialog can have one or more 
pages.
For example, when
importing xls files, the window has a page (tab) for each sheet in the
workbook. Each page contains a table showing the content of the sheet,
without colors, charts or special formats.
In the other cases only one page is showed, with the content of the
imported file or the data in the database result set.
Select with the mouse a rectangular block of cells and click 
Add Selection to Project
to import as a matrix in the project.
During the cell selection it is not possible to 
scroll the table,
but it is possible to continue the selection from another cell pressing
Shift
together with the left mouse button.
Clicking 
Add Selection
to Project you convert the selected block to a matrix.
You need to 
choose
the matrix type and to 
give
its name and package. The matrix created in this way is added to the project.
If
you choose to import the block of cells as numeric or date matrix,
you need to 
set the formats
to parse numbers and dates.
When the import is complete, click the 
Close button to
close the window.