Those are both very common herbal applications for late pregnancy. RRL is a uterine tonic that helps your contractions be more effective, and EPO contains prostaglandins that help the cervix thin out and dilate. I've been doing both since 37 weeks (I'm 39w2d now) and my cervix was dilated about 2cm this past Tuesday, and 60% effaced. They are safe and effective ways to prepare your body for labor. Think of it as removing the road blocks. These things won't necessarily make you go into labor sooner, but they can make it easier to have your baby when the time is right.
Don't worry about how big your baby is. Your body won't grow a baby larger than it can birth. I'm expecting a large baby as well; I weighed 10 lbs 4 oz and my husband weighed 8 lbs 11 oz. But all that really matters is the head size anyway - the body usually slips out easily, so if the baby fattens up its arms and legs, it probably won't matter. The baby's weight will usually plateau around 40 weeks anyway - it probably won't get much bigger.
You should also know that there is no good way to know how large your baby is before you give birth - both ultrasounds estimates and an experienced physician/midwife measuring and palpating your belly are only accurate within a 2 lb range - that's plus or minus a whole pound on either side (and that's only if they are good at it - sometimes they are even less accurate). My sister-in-law was induced at 38.5 weeks because they thought her baby weighed 8lbs already (probably scared because of our family history), and her baby really only weighed 6lbs 14oz. The baby was clearly not ready to be born - she acted like a preemie and had all kinds of trouble with feeding, and they ended up putting her on formula and switching it a bunch of times. She also now has asthma, which is a big risk facing babies who were induced because those final days in the womb are crucial for lung maturity.
Be thankful you have a physician who is recommending natural remedies! If you make it to 40 or 41 weeks, you may want to ask your physician to strip your membranes, which also releases prostaglandins. In the mean time, have sex (without condoms - the semen contains prostaglandins) as much as possible if you are comfortable doing so, and exercise.