An RPG campaign is a collaborative team activity with lots of communication. Many of the things you do in other teams, like at work or school, apply here too. More specifically, here are some things that have worked for campaigns I've been in, whether it was me or someone else who tended to be the talkative one:
- If you're playing in person, monitor the room (so to speak). How are the other players reacting to you? Are they engaging, building on what you're doing, smiling? Are they rolling their eyes, looking at their phones, getting *another* Coke from the fridge? (This is much harder to do on video calls and even harder in text-only modes, and I don't know how to advise you there.)
- Look for ways to use your tendencies to uplift other players, especially the quieter ones. "Hey Turok, what'cha thinking?" or "I'll bet Kyle would know how to solve that" uses your activity to bring others in, so while you're talking, it's not all about you. (When Turok or Kyle responds, cede the floor.)
- Science it: pass up every third or fourth temptation. Back off just a bit, keep the wisecrack to yourself this time, and see what happens. If somebody *else* makes a witty remark (or even a not-so-witty one), that tells you that you might be preventing them from having this kind of fun. If there's silence and play continues, that tells you it might not have added much (nobody missed it). If somebody brings it up in a non-sarcastic way, that tells you the quips were probably welcome.
- Talk with other players about it, *but not during the game*. Ask either the GM or a "mid-range" player (in terms of activity) for a private chat. (Don't ask the quietest person, who might be uncomfortable telling you directly if your activity is a problem.) Tell the person that you're concerned you might be overdoing it, you want everybody to have fun, and you're asking for feedback so you can calibrate your activity. Keep it positive; don't ask if other people "have a problem" with you, which can put people on the defensive a bit. Cast it as seeking self-improvement.
This one's a little unusual, so I'm separating it. In my last campaign, I was one of two players who tended toward the limelight, and I was concerned about it. I loved what the other player was doing, but I didn't assume that people loved what *I* was doing. (He was a much better role-player than I was.) I was also keeping an in-character diary on the campaign's experimental shared blog. I found that the character diary gave me way to express things that added to the *story* but could have disrupted *play sessions*. The diary was completely optional, both for me as a writer and them as readers, and at least one player ignored the whole blog entirely. But for those who wanted to "play" in that way too, it gave a non-disruptive alternative. Sometimes other players posted *their* diary entries or letters to NPCs or something, and (I later learned) the GM was pulling some stuff I just made up into the story and using it.