Try selecting from within the text you want, not before. eg if it's in 2 columns and you start too high it will select both columns.
Also Firefox has a control select mode (ie hold down the control key) that allows you to select vertical/horizontal table columns.
If it's a simple block of text that you want the right side of every line (from some arbitrary point) then you'd have to paste it into something and strip out the start of each line yourself.
