That's not particularly large for a regularly used site. Images are more likely to take up space than the database.
They look like 2 different databases, one has the prefix 'jamroom_' the other 'jr_'. Best to figure out which you are using for your site, you can probably delete the other.
Deleting anything will loose something from your site. eg that jr_jrcomment_item_key is the comments people have made. it works in conjunction with the jr_jrcomment_item table, so those 2 need to be kept in sync.