I've been dealing with low stamina, some knee pain and weak bones - can a multivitamin tablet with minerals and trace elements help with this?

Those three symptoms together often point to some nutritional gaps, so it's a reasonable thing to explore. A multivitamin tablet with minerals and trace elements can support energy levels and bone health if you're falling short on certain nutrients, but it usually works best alongside diet, activity and addressing the specific cause of the knee pain. I'd get some basic blood tests done and talk it through with a doctor, so they can tell you whether a supplement alone is enough or something else needs attention.