attributes by definition are a part of a block
As mentioned in my original post, I want to add attributes without making it a block.
Then you'd be adding "text entities" because to have "Attributes" means that you're also dealing with a block. You can't have attributes without a block. You can put text entities besides your polylines that would make them appear as attributes, but again....they'd be text entities and not attributes. In fact as far as I know the only thing that separates text entities from attributes is if they're belonging to a block=attribute, not belonging to a block=text entity.
Or, in short, and in response to your original post / question of "Can we add attributes to a polyline without making it a block" ..
Answer: No. you can add text entities and "group" them with your polyline to create attribute-esqe entities...but if you're looking for functionality to where you can doubleclick anywhere on the polyline to have the text editor dialog pop up for the text entities, then I think your best bet is to simply start using block objects