// Get cell range by the specified coordinates
var range = tabSheet.getRange(1, 0, 1, 2);
// Unmerge range cells
range.split();
var cellSpan;
// Determine table model
var model = tabSheet.getModel();
// Determine range corner coordinates
var corners = range.getCorners();
// Determine range size in pixels
var size = range.getSizeInVirtualCells();
// 
if (range.getCoordsCount() > 1) {
    // Create a cell span
    cellSpan = new PP.Ui.TabSheetCellSpan({
        Data: {
            "@T": corners.tlCoord.rowIndex,
            "@L": corners.tlCoord.colIndex,
            "@W": size.columnsCount - 1,
            "@H": size.rowsCount - 1
        }
    });
    // Add a cell span to model
    model.addCellSpan(cellSpan);
}
// Set new table size
tabSheet.setHeight(300);
// Clear borders of the cell span
cellSpan.clear();
// Refresh table
tabSheet.rerender();
// Select the cell span
tabSheet.select(cellSpan.getRange(tabSheet));
// Get coordinates of the cell span
console.log("Cell with coordinates (" + cellSpan.getCoord().colIndex + "," + cellSpan.getCoord().rowIndex + ")");
// Determine size of the cell span in pixels
var sizeInPX = cellSpan.getVisibleSize(tabSheet);
console.log("Width: " + sizeInPX.width + "; Height: " + sizeInPX.height);
// Determine span size in cells
var sizeInCells = cellSpan.getSizeCoord();
console.log("Number of columns: " + --sizeInCells.column + "; Number of rows: " + --sizeInCells.row);
// Determine whether the coordinates (0, 1) are in the cell span
var coord = tabSheet.coord(0, 1)
if (cellSpan.isCoordInSpan(coord)) {
    console.log("The coordinate (" + coord.rowIndex + ", " + coord.colIndex + ") is in the cell span.");
} else {
    console.log("The coordinate (" + coord.rowIndex + ", " + coord.colIndex + ") is not in the cell span.");
};