mysqldump: dump several tables from db. what will be locked?
Given the current way you are doing it

mysqldump -u.. -h.. -p... mydb tbl1 tbl2


each table is locked during the SELECT phase in a specific way

Note the effects during the dump


Each table that is MyISAM should allow SELECTs but block INSERTs, UPDATEs and DELETEs
While dumping tbl1, tbl2 is fully accessible
While dumping tbl2, tbl1 is fully accessible


If those tables (tbl1 and tbl2) are inactive, then such a dump would be harmless to busy tables.