When you are doing left join.. all the data will be append to the left Table.
In Your case,
Your joining the 'temp' table with 'SpecificLoans' table. Then the result will be stored in 'SpecificLoans' and
'temp' table no more exits. After that you are renaming the 'temp' table which is not exists.
So you got the error 'Table not Found'.
You join the table temp to the table SpecificLoans, so there is not table temp to rename.
If you only want to load thoses datas which are in the excel file load
(ooxml, embedded labels, table is Sheet1);
where exists ([Loan Number],acct_nbr);
drop table Loans;
drop table SpecificLoans;