Can I use VLOOKUP to find all instances of a number in column1 - and add all of in column3?

Hi. First time here, - just getting back into excel and I'm hoping I can achieve this without VBA!

My file has two tables and I'm using VLOOKUP to propagate names from table1 'student number' column (column 1), into table2.

Now, I want to be able to identify all instances of a student number in column1 of table2, then add-up all numbers in column 6 (for those records only) and put that number into a cell in table1.

Can anyone tell me if/how this might be possible please?

Many many thanks!