To merge cells in the group header/group footer/table footer panel, select adjacent cells, right-click and select Merge (or click the Merge button on the Standard toolbar).
To unmerge cells, right-click it and select Unmerge from the shortcut menu. The cell will then be split into multiple cells.
Unmerging is the reverse operation to merging, and therefore only previously merged cells can be unmerged.
To format the borders of a table cell, take the following steps:
Specify whether the borders will be displayed or not by checking None, Box or Custom. If Custom is checked, you can click , , , or to set the visible/invisible status of the left, right, top, or bottom border.
Specify the border color from the Color drop-down list. If you want to use a formula to control the color, click and select a formula from the drop-down list. If the given formulas cannot meet your requirements, click <Create Formula> to create one.