In a situation like this you would want to avoid using the following logic as it actually goes through and counts each individual row.
SELECT count(*) FROM TableA
Instead using the system tables you can get an accurate and extremely fast list:
select t.name as TableName
, i.rows as Records
from sysobjects as t
JOIN sysindexes as i
on i.id = t.id
where t.xtype = 'U' and i.indid in (0,1)
order by TableName
This query works for SQL Server 2000 and greater.