Toddler throws everything off the table, window sills, etc.

Hi, we're really at our wits' end here. Our 2.5-year-old daughter is currently throwing all our stuff. The plants are getting knocked off the table, the flower pots and decorations are being pulled off the window sills, and the fairy lights (which obviously don't even light up) are getting broken. I'm going completely crazy. We're trying everything from ignoring it to firmly grabbing her arm, to sending her to timeout, but nothing works. If you ignore it, she just keeps throwing things. If you punish her, she just walks over and does it again. The annoying thing is that she just does it out of nowhere, whether we're playing together or she's playing on her own, whatever. Is this a phase? Does anyone recognize this? How did you handle it? I understand that she's testing boundaries, but I don't want to put all the stuff away. She needs to learn to leave it alone, right? It's such a shame because so much has already been broken, even a piece of furniture that was already damaged.