One item or record is going to have many tags or keywords. And one tag or keyword will belong to many items or records. So to implement this scenario or pattern, we need an intermediary table to overcome the many-to-many obstacle.
Table: ItemsColumns: Item_ID, Item_Title, Content
Table: TagsColumns: Tag_ID, Tag_Title
Table: Items_TagsColumns: Item_ID, Tag_ID
{To store or maintain, tags<=>items associations}