40 mg is a low dose for that medication. I used to be on 320 mg a day. Yes, it will drop your bg quite successfully, and hypo is possible on this med. You did the right thing with both the jelly babies and the biscuit. Jelly babies give a quick boost to the sugars, and the biscuit provides longer-term protection until the med is used up/ excreted (It takes a few hours for that to clear)
If you are a driver, then you need to read the DVLA guidelines for diabetics on medication. You do not need to notify DVLA at this stage,
I am still using one x 40mg tab a day and it drops my bg by between 2 and 3 nnil/l after a meal. With alcohol, it can drop by up to 5 mmol/l so go carefully if you are a vino imbiber with your meal. I used to carry glucose tablets on me when I was on max dose, but now I don't bother. My hypos were quite mild and for me, easy to deal with , I have a locked drawer with choccie wafer biscuits (locked because my daughter used to raid my stash and leave me with no hypo kit).
You may even consider getting a pill-splitter since this tab is not coated or slow-release, I use the fact that my bgl drops as it does as proof that my beta cells are still producing insulin even after 30 years of T2D abuse.