So you are publishing this report from Tableau Server using Tabcmd? I will move this thread to Server Administration where other admin's often assist.
Do you have a small sample workbook that you could share as well so we can see your dashboard setup? Packaged workbooks: when, why, how
You can also specify the page style (letter, legal, tabloid, etc.) and dimensions when exporting to pdf. Follow the instructions in this article and let us know if you have questions. If you give us the code you're using, we can take a look.
This is the command I am running:
tabcmd export "Monthly/GMV_Ordenes_Mensual?:Mg_Site_Default=ar&Manufacturer=P_%26_G" -fullpdf --pagelayout landscape --pagesize a4
Do you have an email so i can send you the report?
I dont want to publish here that information.