Hello!! Does anybody know where one can find the list of the available tables for SuiteQL and their relationships?

Please go to here. https://system.netsuite.com/app/recordscatalog/rcbrowser.nl

Thanks Mark for the Hint but record Catalog is not complete. For example the data for transaction lines is split among at least two tables, TransactionLine and TransactionAccountingLine. The latter is not even mentioned in Records Catalog. For example, by gathering suggestions from various posts on the Internet, I wrote the following query:

SELECT 
mRecordType, 
mTranId,
mTranDate,
mAccount,
mType,
mAccountNo,
mDebit,
mCredit,
mMemo,
LISTAGG (cAccount, ', ') WITHIN GROUP (ORDER BY mTranId, cAccount) as counterAccount
FROM (SELECT DISTINCT
Transaction.recordType as mRecordType,
Transaction.tranId as mTranId,
Transaction.tranDate as mTranDate,
BUILTIN.DF( TransactionAccountingLine.Account ) AS mAccount,
Account.acctType as mType,
TransactionAccountingLine.Account as mAccountNo,
TransactionAccountingLine.Debit as mDebit,
TransactionAccountingLine.Credit as mCredit,
TransactionLine.Memo as mMemo,
cAccount.accountSearchDisplayName as cAccount
FROM
TransactionAccountingLine
INNER JOIN TransactionLine ON
( TransactionLine.Transaction = TransactionAccountingLine.Transaction )
AND ( TransactionLine.ID = TransactionAccountingLine.TransactionLine )
INNER JOIN Transaction ON TransactionLine.Transaction=Transaction.ID
INNER JOIN Account ON TransactionAccountingLine.Account=Account.ID
INNER JOIN TransactionAccountingLine AS cTransactionAccountingLine ON TransactionAccountingLine.Transaction=cTransactionAccountingLine.Transaction
INNER JOIN Account AS cAccount ON cTransactionAccountingLine.Account=cAccount.ID AND cAccount.acctType!='Bank'
WHERE
TransactionAccountingLine.Debit IS NOT NULL  OR  TransactionAccountingLine.Credit IS NOT NULL 
)
WHERE
mAccountNo =1570 AND
/*mTranId = 'JE3760' AND*/
mTranId !='JE12'
GROUP BY 
mRecordType, 
mTranId,
mTranDate,
mAccount,
mType,
mAccountNo,
mDebit,
mCredit,
mMemo
ORDER BY 
mTranDate,
mTranId

Ah!!! Thank you. I expected that all the tables were searchable in the search field. That's why I said they were not available. I'll have a deeper look at that

Annoyingly, some ARE missing, but you can sometimes find them by directly editing the URL