I have deleted many custom filed but it show like this

If you have added any custom Data fields then you can convert them to Small Text to reduce row size.
kindly refer this document
https://docs.erpnext.com/docs/user/manual/en/maximum-number-of-fields-in-a-form#solution

Here i have deleted about 30 fields which was customily created but the database row size remains the same is there any other way rather than deleting the fields (which is already deleted from UI)directly from database