Although you cannot pause the time in the lab, you can request up to 8 one-hour extensions. Please understand that each module is independent. It is not necessary to pause the lab. Just complete one module during your session.
All lab manuals can accessed here: http://docs.hol.vmware.com/
For HOL-SDC-1608, the pdf is here: http://docs.hol.pub/HOL-2016/hol-sdc-1608_pdf_en.pdf
HOL-SDC-1402 and HOL-SDC-1425 are based on vSphere 5.5.
The link with the downloadable PDF file doesn't work - is the ability to download a document with the lab context no longer available?