What could it mean when i have non painful, non discoloured lumps on both sides at the back of my tongue?

Perhaps Normal: All of us have non-painful lumps on the sides & back of our tongues. So, what you're seeing could quite possibly be "normal" anatomy. However, there are many variations which look a bit odd, & there are also several conditions which could look as you describe. The only way to know for sure is to see a dentist, oral surgeon, or ent. If it's something unusual, you should know asap. See someone asap.