It's a bit of a hack as Query Studio is really all about making it easy to get data and doing anything with layout is really a job for Report Studio, but you can do the following:
a) create a calculated column on a text field. Select 'Concatenation' as the operation and put a space as the preceding text. Click ok
b1) right-click on the new column and select 'Format', then 'Text' and enter 1 for the number of characters
or
b2) create another calculated column from the first calculated column, set it to 'first characters' and enter 1 for the number of characters. The first calculated column can now be deleted.
Both of these approaches will give a column that only contains a single space - not actually blank but close enough for most purposes. The first approach is a little quicker but may result in the text still existing in some output versions (e.g. csv) - I'd need to do more testing to confirm.
The column title can be edited (to be set to blank) by double clicking it, of course.