>>Hit Edit on grid,
>>then select column and press Delete key.
>>You would be prompted to delete this column and all objects.
>
>??? Sorry, can you explain me some details. I can do it with mouse right-click and the grid becomes rounded with some green rectangle. In my Properties window I select the column and when I press the "Delete" key nothing happens. Hm?

Don't select it in Properties window, select it in the Grid itself while in editing mode.