In many daycares and preschools, that child would be gone already, the parents told that he or she is not ready for the group setting. While most kids might bite at one time or another, any one kid biting this much is just nowhere near ready to be in a group like this. Some daycares have specific limits on the number of times a kid can bite before the parents are told to remove the child from the program, period.
Google on the terms "day care biting policy" and you'll see that MANY daycares/preschools have a firm policy that you should be notified every single time your child is bitten and especially if the skin is broken. Have you been notified? Does the daycare have a written policy on biting? It should--many do, so try the search. There are also some daycares where repeated biting is grounds for the center to dismiss that child and that's in writing too.
So--why has your daycare allowed it to go on? Does it have a policy but they're ignoring it? Why even ask if it should be tolerated for this age? I'd ask instead: Why should it be tolerated for a kid to be bitten 10 times and nothing done except a "kids will be kids" attitude? Yes, some kids bite, but if the daycare isn't able to figure out the biter's triggers, distract the biter, and help the biter "use your words" when frustration hits, I'd question whether this daycare/preschool had well trained staff anyway and whether it was understaffed or had too many kids.
You could print out sample daycare biting policies, get other parents to back you up in person, and go see the director to request that there be a clear, written policy in place regarding biting, how adult staff should handle the child, when parents should be notified, and what could make biting grounds for a child's dismissal from the daycare. That could be an excellent benefit to ALL the kids and famiiles, IF you have a receptive director or owner. This can only be really effective if you don't do it alone and have other parents there next to you, and if you also are clear that the biting is at a point where you will pull your child out of this daycare and take your child (and your daycare dollars) elsewhere very, very soon if your child is bitten again.
If there is blowback or waffling from the director, I'd walk immediately, and be clear that the biting is the reason why. I know that's easy for me to say and hard for you to do, since maybe day care slots are hard to come by where you live, etc. That's why you could consider taking the lead on pressing for a written policy on biting immediately, or for enforcing the policy if one already exists. But taking away your business is your main leverage here. If you move to another daycare, I'd ask up front if they have a written policy on biting and how they enforce it.
In your situation, I probably would already have removed my kid and been very frank about the reasons why, but again, that's easier to say than to do.
Some daycares take this so seriously they have protocols for how to wash the bite, they require written reports go to both kids' parents (biter and kid bitten) that same day, they call for follow-up if skin is broken and a child has to go the doctor, etc. Some daycares with serial biters have a policy that an adult will "shadow" the biter to monitor the child. Does your daycare have that level of attention?