Paul is not being sarcastic. This is his legal defense. He is referring to the events you mention from chapter 23 and earlier. In 24:10ff Paul testifies to Felix the governor in his own defense. The High Priest Ananias ben Nedebaios brought some other elders and Tertullus, an orator who would be skilled in Roman legal proceedings, to bring charges against Paul (24:1). They present their accusations to Procurator Marcus Antonius Felix in verses 2-9. They accuse him of being a troublemaker (literally λοιμὸν-"plague" or "pest"), instigating riots, and attempting to desecrate the Temple.
It is also worth noting that Tertullus addresses Felix with the typical honorific for his office, "most excellent." His reference to Felix's rule as a time of peace and progress brought about by Felix's skill as an administrator is complete flattery and utter balderdash. Josephus records that Felix's rule was a time of escalating violence (War 2:253-270; Antiquities 20:141-143, 160-177 [see especially 162]). Tacitus, a Roman historian, concurs and lays the blame for the violence at Felix's feet (Annals 12.54, "Felix..., by ill-timed remedies, stimulated disloyal acts", History 5.9).
When he makes his defense, Paul says that he is aware of Felix's reputation (24:10). Paul then does not use the honorific for Felix; however, he is quite willing to address Felix's replacement by it (Acts 26:25). Paul lays the burden of proof on his accusers. He proclaims his innocence in all the events they accuse him of and tells Felix that he can find witnesses to verify Paul's side of the story. He then turns to a positive self-defense. He freely admits to being a Follower of the Way and shows how he disagrees with it being a sect.
Paul then notes that the men who accuse him of instigating the riots of 21:27-28 were not even present at the court (24:19). In principle, Roman law required eyewitnesses. Paul's case is made stronger by his accusers claiming they have found him guilty but not bringing their witnesses. Jewish law absolutely required eyewitnesses for crimes like Paul was accused of (Mishnah Sanhedrin 3:6; 4:5; 5:1; Ketuboth 2:2; Bekhorot 4:10; Rosh HaShanah 1:8; 3:3; Makkot 1:8; Eduyot 2:7, etc.; BT Rosh HaShanah 20a, 21a-22b, 25b, 23b-24a; Sanhedrin 6b, 8a, 8b-10a, 17b, 23a-23b, etc.).
24:17 "After several years I came to bring to my people gifts for the poor and to present offerings, 24:18 which I was doing when they found me in the temple, ritually purified, without a crowd or a disturbance. 24:19 But there are some Jews from the province of Asia who should be here before you and bring charges, if they have anything against me. 24:20 Or these men here should tell what crime they found me guilty of when I stood before the council, 24:21 other than this one thing I shouted out while I stood before them: 'I am on trial before you today concerning the resurrection of the dead.'"
Paul completes his defense by noting that the elders accusing him are eyewitnesses to his time before the Sanhedrin and that they should provide a list of crimes they found him guilty of then. He freely admits that his actions caused a division of the house in that trial and ended proceedings.
Paul is admitting that the only disturbance he is guilty of was the one which caused the Sanhedrin to adjourn that day.