It is perfectly normal for a developer or senior engineer or someone else to run a meeting when the normal person running the meeting is going to be out. (Or, where I work, when they are there, but want someone else to get the practice.)
It sounds like it is a normally scheduled meeting, so the schedule and invitations are probably already set - you just have to be the MC, so to speak. If there is a regular agenda, that limits your responsibility even more.
But, you're not comfortable in this role, and don't want to do it.
You can go to your team lead, and ask for their guidance. In fact, you should anyway, so they know that was put on your list of responsibilities. They might offer to run it instead (doubtful). If they agree that you are to run it, then you'll need to run it. It's a bit late to suggest Toast Masters so you are more comfortable speaking in front of people, but since it is a regular meeting, you probably don't have to do more than direct the meeting so you keep on the agenda. It could go something like this.
X asked me to lead the meeting today, as he is out. We already have the agenda, and the R&D Dept is supposed to start with their update.
Then, let them talk. If they seem to get off topic or are going so long that there won't be time, you can interrupt...
Could we get back to the topic on hand? (or) We have a lot of topics to get through, could you wrap this up in the next few minutes so the next department can give their updates?
If you've been paying attention in previous meetings, you should have an idea of what the meeting leader does. Unless the normal leader spends a lot of time talking, you just need to direct the rest of the people to follow the agenda. And if he does normally spend a lot of time talking, you don't have to -- follow the agenda, and end the meeting a bit earlier. People will not be offendend.
Going to HR is a bad idea - it makes you look like someone who isn't willing to step up and expand your skills. Speaking in front of people and running meetings are useful skills, even for developers.