?Can you include oral presentations and posters presentations on ERAS if you weren't the presenter?
If you are a listed author, heavily involved in the research, and participated in writing and submitting the abstract, then go ahead and list it.
If an abstract is accepted to a meeting, especially as an oral presentation, it speaks to the relevance and quality of the research. I think you should get credit for your part. List the project under "Oral Presentations" in ERAS and put (presenter) after the name of the person that gave the actual talk. Do the same with poster presentations in which you were involved but did not actually give the presentation. If you gave the presentation, then put (presenter) after your name.
Be prepared to be asked what your role in the project was, and be honest.
If the same data set was presented in more than one venue, or even eventually published, my answer might change.