Why does my dog bring me 'offerings'?

My family calls them 'offerings'. Whenever I get home, she runs and greets me, tail wagging so hard her butt's wagging. I pet her, she runs in circles, and runs to fetch something to give me. Usually a toy of hers, but failing that she'll grab towels, pants, hoodies - anything that belongs to me. It's starting to happen even when I praise her in the house. She runs and grabs something to give me. Why does she do this?