I have found that if you carefully highlight the entire table (keywords and all the other data) and then paste into a spreadsheet it does seem to format correctly so all the keyword/topic suggestions are in a single column on separate rows. You can then delete all the other columns, or keep them if you want to save that information.
Setting the 'per page' to 100 at the bottom of the Topics page will minimise how many copy-pastes you have to do.