Try specifying the column numbers you want to read as rcols 'filename', $column_number, $another_column_number, { OPTIONS => 'values' }:

pdl> print `cat test.ts`;
1       0       0.1000  0.1000  0.8000
 1      0       0.1000  0.1000  0.2750  0.5250
 2      0       0.1000  0.1000  0.8000  

pdl> ($a, $b, @rest) = rcols 'test.ts', 0..5, { COLSEP => "\t", PERLCO
+LS => [0] }; print pdl($a), $b, pdl @rest;
Reading data into piddles of type: [ Double Double Double Double Doubl
+e ]
Read in  3  elements.
[1 1 2] [0 0 0] 
[
 [  0.1   0.1   0.1]
 [  0.1   0.1   0.1]
 [  0.8 0.275   0.8]
 [    0 0.525     0]
]


pdl>
[download]

Is this what you want?

_{Edit: changed the way of printing the gathered values a bit}