Show GridView data in Matrix format in ASP.Net

Hi all , i have a small query. in my query i have gridview with checkbox, category .in page load my gridview show the rows like

checkbox table checkbox chair checkbox books checkbox cds..... etc..

this is the order of gridview. in my query i need to show above gridview in pageload like

checkbox table checkbox chair checkbox books checkbox cds

like matrix form how to solve above query... plz help me

Thanks in advance