Sometimes we create ad groups and keywords with the help of ACM feed. In that case your keyword column takes reference from the feed columns or template. Might be while using that feed template some combinations were not defined well, so it is showing those reference in your keyword column.
Another case is accidentally anyone uploaded those terms as a keyword.
Another likely reason you're seeing "(adgroup content) <ad group name>" in your keyword report is that a campaign included in your report is opted into the Google Display Network. You can confirm this by checking the "Listing Match Type". Display network will be labeled "Content" in this column.