I'm trying to optimize my site and notice that one of my competitors appears in all of the top 3 results same domain, different pages.
Is this normal or considered an abuse?
Does anyone have any comment about this can I should I report it?
There's no violation of any sort for just being on multiple ranking in the first page.
Here's an example
If there isn't any sort of spamming, backlink abuse or other blackhat practice, it's completely legit.
Here's some words from Matt Cutts that answer all your doubts. https://www.youtube.com/watch?v=sxv-AvNPoh8
As he said, if a domain has very high quality pages about a topic, even if Google prefers diversity, they can show people resources from that domain in multiple rankings.