Hello Balamohan,
I have tested the scenario using following code snippet and as per my observations, the text inside table cell is automatically wrapped to next lines. Can you please take a look over the following code snippet. I have also attached the resultant PDF document for your reference.
[Java]
//Instantiate a Pdf object by calling its empty constructor
Pdf pdf1 = new Pdf();
//Create a section in the Pdf object
Section sec1 = pdf1.getSections().add();
aspose.pdf.Table table1 = new aspose.pdf.Table();
sec1.getParagraphs().add(table1);
table1.setColumnWidths("70 2cm");
Row row1 = table1.getRows().add();
Cell cell1Row1 = row1.getCells().add("Text in this cell is spanning");
cell1Row1.setColumnsSpan(2);
cell1Row1.setBorder(new BorderInfo(BorderSide.All.getValue(), 0.5F));
// save the PDF file
pdf1.save("d:/pdftest/CellTextSpanIssue.pdf");
PS, I have tested with Aspose.Pdf for Java 2.5.0