Can we add the Table by ourselves like we need to add the Report- Like Trial Balance, or General Ledger Balances, or Stock balances
you can go to the erpnext ui and search fr insights table and try too add it from there
Tables and Doctypes in frappe/erpnext have one to one relationship.
Since general ledger is a report (not a doctype) there’s no table for it
General Ledger is a complex report, you won’t be able view the same data as it is in Insights without a writing a complex SQL
However you can get basic debit, credit data by querying GL Entry table