Use HTTPService with resultFormat="text" and your file will
be returned to you as a single String.
The String class has a splice function which can break a
String into an Array of Strings. You'll want to first splice the
string by the newlines so that you create an Array of Strings, each
which make up a row.
Then use a for-loop over that Array and splice each of those
Strings by tab ("\t") and that will give you an Array of each data
field. Put that Array into an ArrayCollection which will be the
dataProvider for your DataGrid.