There are three major theoretical differences between temporary tables and table variables
The first difference is that transaction logs are not recorded for the table variables. Hence, they are out of scope of the transaction mechanism.
The second major difference is that any procedure with a temporary table cannot be pre-compiled, while an execution plan of procedures with table variables can be statically compiled in advance. Pre-compiling a script gives a major advantage to its speed of execution. This advantage can be dramatic for long procedures, where recompilation can be too pricy.
Finally, table variables exist only in the same scope as variables. Contrary to the temporary tables, they are not visible in inner stored procedures and in exec(string) statements. Also, they cannot be used in an insert/exec statement.
Irrespective of above differences, if data load is less, @table (table type variable) will work better than #table (temp table) and if data load is more, #table will work better @table.
