After the age of about 18 years you won't grow taller - it's a physical impossibility. The ends of the long bones (thighs etc) have fused with the shafts (the shafts lengthen during growth and that's what makes you taller) and that's the end of linear growth, even with Human Growth Hormone injections.
A vibration plate will improve bone density in the same way that other weight-bearing exercise will - things like running, walking etc. Bone density gives the bones their strength by making their honeycomb structure more dense. Intake of calcium (eg diary) Vitamin D (sunlight) and discussing hormone replacement with your doctor if you're post menopausal will help this.
To improve height - or perceived height - try the Alexander Technique which improves posture and body alignment which will make you appear taller.