To reproduce : 1. Type some words in Writer with one font. 2. Save without embedded font. Here : 7.9 kB. 3. Save with embedded font. Here : 4.6 MB. In the file, eleven (11) ttf fonts file are embedded in instead of one used ! So, it is needed to embedded only a subset of each fonts. Better, the user should have the choice if he wants all fonts embedded (to shared works with other in this file) or only a subset (by default). Exporting to PDF files get subset of fonts, I think that the work perhaps is yet started.
Test file are here : File with embedded font : http://rpnpif.free.fr/fichiersDivers/essai-with-font.odt File without embedded font : http://rpnpif.free.fr/fichiersDivers/essai-without-font.odt
Did the same observations. Set as enhancement. Best regards. JBF
*** This bug has been marked as a duplicate of bug 70669 ***