Comment 5 for bug 1013484

eklavya, you can solve the problem by uninstalling the package libreoffice-gtk. This will make the tabs in libreoffice calc look the size they are but will also make libreoffice look "out of place". That demonstrates that is not a libreoffice bug, it's an elementary theme bug. It happened the same to me using Adwaita Cupertino theme in ubuntu a few months ago but, in that case, after submit the problem to the developer of the theme, he fix the theme in a couple of days, and the theme still looks nice. Sadly, I think that won't happen here.