Hi,
Just provide the answers from my personal end:
Q1:
The lab session is mentioned for 3 Hrs & 30 minutes. Does it mean it will have to be continuous 3.5 hours. or I can work in split timing totaling 3.5 Hrs?
Answer:
It’s continuous 3.5 hours, you cannot split it.
Q2:
What is the difficulty level of lab assignments? are they similar like assignments in level 3 - advanced developer training or much harder?
Answer:
The difficulty is the same as level 3 and also based on ACME system.
Q3:
What is the process of lab test assignment submission? is it same like level 3 - video submission or we will have to submit exact codes?
Answer:
Zip ALL the used workflow files AND the output Excel file. Then upload the .zip file to the UiPath Certification Platform.
Q4:
Is there any time limit by when I have to pass the lab test after clearing quiz?
Answer:
The certification is free before 31/12/2018, you would better finish it before it…
Q5:
any practical experience, guidelines or sample lab test will be really helpful.
Answer:
Just finish the two assignment of level 3 by yourself … Relax, not difficult 
Best Regards,
Aisling Bai