You can further customize your table by joining and splitting individual cells. The Join and Split Cells tools are found on the Table tab.
To join multiple cells in your table, highlight the cells you want to join then click Join Cells.
Joining a cell combines any text in the cells into a single block of text. When cells from multiple rows are selected, cells adjacent to each other in the same row are joined first. Cells adjacent to each other in the same column are joined only if they have no selected neighbors in the same row.
Joining cells in the same row simply removes the cell divider(s) between them.
Joining cells in the same column creates a single cell that spans the rows containing the selected cells. Cells that span more than one row always span a whole number of rows.
Alternately, to split cells that have previously been joined, click on the cell in your table then click Split Cells.
If a cell spans more than one row, splitting creates a cell for each row spanned. Any text in the split cell is placed in the top, or left, cell.
If no selected cell spans more than one row, all selected cells are split into two cells within the same row and occupying the same space as the original cell: A vertical cell divider is added to the center of the cell.