Keyboard Issue

This is my third Dell. I have an Inspiron17 R; my second laptop. Has anyone experienced problems with the keyboard? The cursor jumps around or whole paragraphs are deleted without cause. I have been typing for more than 50 years and you can feel if you make a typo. Unless I can find a solution for this issue, this will be my last Dell.  Much of my work is done through email.  Even after saving my previous paragraphs, suddenly the cursor will jump and all my work is lost.  Unbelievable!  I would appreciate any assistance offered.