This depends very much on your OCI process. Talk with your career services people.
At my school, I'm limited to 60 applications. I'm then limited to 25 actual interviews. I think there were 400 or more places to apply with. I'm using up all 60 applications, and hoping to fill all 25 interviews. The way the system is set up, I may be required to refuse interviews with some firms. For this reason, the school has the interviewers select primary candidates equal to the number of interview slots, then secondary candidates who get to sign up in the remaining slots on a first-come, first-served basis.
If your OCI is truly open-ended, remember you are getting yourself a job, not your classmates. Don't bother interviewing with places you can eliminate based on city, practice area, salary, etc.
The firms themselves will also do some sorting of candidates. A firm which has never been able to hire from the top 25% at your school will not fill up all their slots with top 10% folks. They might pick a token few, but will then fill the rest with students who have lower grades but are more likely to accept.
Whatever you do, clarify what your Career Service office requires and recommends. You don't want them pulling all your interviews because you did something against their rules.