I am unable to create Fields on crmd_orderadm_h table due to size limit data baselimit?

Hi Team,

Unable to create AET fields on crmd_orderadm_h table due to size exceeds of the table but my total fields of  crmd_orderadm_h is 168 fields only ,but it is not allowed to create.i am getting error like as below.please help here.

Thanks

Kalpana