I have been trying to get design tables working on my installation of SW2013 SP03 and, subsequently SP04 but with limited luck. When adding a design table, SW would pretend it had, but nothing actually happened. When adding a design table from an existing .xls file, it would either return with a "create package" dialogue box (I can't remember precisely the wording) or it would crash out SW entirely.
So, after some time working with Darren at Solidtec Solutions support (Melbourne, Australia) we finally managed to get it to work. The solution was to reinstall MS Office (2010 for Home and Business in this case) as the 64-bit version. I had to actually ring Microsoft to get a hold of a download link for the 64-bit version, but in the end this appears to have solve the problem.
MS Office 2010 seems to install as a default configuration as 32-bit, despite the presence of a 64-bit OS. There are some minor compatibility and function differences between the 32 and 64-bit versions that MS outlines on their support pages, but for me, it was a fix. It may be that some have functional design tables with the 32-bit version - if so, this message is not for you! For those who are frustrated with this issue - try a 64-bit install for Office!