According to the Oklahoma State Election Board (via Twitter):
This video is from pct 469 / subpct 457 in Tulsa County. These are clearly "spoiled ballots" where the voter mistakenly marked more than one option in a race. Spoiled ballots are returned to the precinct clerk and destroyed, then the voter is issued a new ballot.
They use screenshots from the video to highlight this point. Here are some of the examples they show - they annotated the video to circle the part of the ballowballot that shows it is "spoiled":
They also referenced the relevant statute:
"Should a voter spoil any ballot in an effort to vote the same, the voter shall... return it to the clerk. The clerk shall destroy the ballot in the presence of the voter and shall issue the voter another ballot..."
And they show a redacted photo of the spoiled ballot affadavit for that polling location, with signatures of 11 voters who had spoiled ballots: