I'm from the State of Kuwait and hold an Eritrean passport. I'm planning to visit UK in October but my visa will expire in November.
Is it OK to make a journey in the last month of my visa, provided that I make sure that I book my plane back before expiring date?
An entry clearance expires on midnight of its expiry date. A visitor with an entry clearance is able to enter the UK on any date up to and including its expiry date.
There is nothing particularly special about an entry clearance with a month or so of remaining leave, people come and go all the time. The only exceptions are when your circumstances have changed or when the premise of your visit no longer exists. You signed an agreement with the UK government about that so you know how to detect those conditions and what to do if they happen. You didn't mention anything in your question about it so presumably those conditions are irrelevant.
Your landing interview will be focused on Part 9 of the Immigration Rules, but this is normal. As always, you should bring the same documents you used to obtain your entry clearance and have a reasonably sound premise, but this is generic advice for everyone. All other things being equal, it's fine.
