When I use Insert > Columns... I can specify which columns from data table X I want to add to my data table A. However in the Source Information of A Spotfire remembers it the other way around and stores the columns that were ignored. This is an issue when the data table X changes. When you refresh data table A, you will get more columns as new columns in X will be added since they are not listed in the ignored ones.
Actually, I disagree. I think it is good that Spotfire remembers the ignored columns, exactly for the same reason the poster doesn't like it :-) However, it might be good to have an option after refreshing to remove the newly added columns. But it should be an Option.