You can select adjacent cells, then merge them into a single cell. Conversely, you can take a large cell and divide it into individual cells.
Select the adjacent cells.
Choose \<emph\>Table - Merge Cells\</emph\>.
Place the cursor in the cell to be split.
Choose \<emph\>Table - Split Cells\</emph\>.
A dialog allows you to split the cell into two or more cells, horizontally or vertically.