In my GCSE's I achieved predominately pretty good grades, As and Bs for the most part, with a singular A* and a couple of Cs, however, one subject and grade really stands out and is appalling; I got an E in Product Design. Obviously this makes a potential application or a CV look that much worse, so is there any way I can simply not include Product Design on my CV/Uni application? Can I just put down under where I say my GCSE's 9 subjects and grades rather than 10? Thanks in advance.
You can leave it out on a CV but not UCAS
Is this grade on the same certificate as your others? Generally, they are. If so, then you can't leave it out, because if they ask to see certificates (and many places do) they will know you tried to hide it.
For UCAS, you must include all grades. But if this is irrelevant to the subject you're applying for, then most unis won't care.
I'm pretty sure that you can't leave it off your uni application. But you can leave it off your CV, the only grade I have specified on my CV is my degree.
You could say 9 GCSE's and completely omit it, or 10 and not include it. Either way there is a small chance that you will get asked about it. (for CV's and interviews that is)
You have to put it on UCAS, so whether Cambridge care or not is out of the question. You can definitely leave it off your CV - most people only put e.g. '10 GCSEs grades A*-C' on their CV, and perhaps specify english and maths.