To remove tabs, drag them below the ruler line. To move them, drag them. To add new ones, select the type in the leftmost pop-up menu and then click in the tab line where you want to put a tab stop. Tabs are either Relative or Absolute. Normally you should use relative tabs so that if you need to adjust margins, the tabs will stay reasonable.
Absolute tabs mean the tab set distances are measured from the edge of the page.
Note that Word Perfect includes Left, Right, Decimal, and Center type tabs. In addition a dot leader may be used for each type. This has no affect on any of the other lines of the paragraph. If you hit this button or key more than once, the whole paragraph is indented that number of tab stops. Note that this button does not affect the right margin for the paragraph.