Difference between Table1 and Table2

[novicenew]

I have a 2 tables, both has the same column names col1, col2. Table1 has more data (1000) and Table2 has subset of Table1 (300). I am trying to get the rows into another table which are exists only in Table1.  I only want the difference, But I always get entire Table1 or Table2. 

let
Source1 = Table1,
Source2 = Table2,

DistinctTable1 = Table.Distinct(Table.SelectColumns(Source1, {"col1", "col2"})),
DistinctTable2 = Table.Distinct(Table.SelectColumns(Source2, {"col1", "col2"})),

Difference = Table.RemoveMatchingRows(DistinctTable1, Table.ToRecords(DistinctTable2), {"col1", "col2"})

in
Difference

What is the mistake I am doing? 

[HotChilli · Accepted solution]

Merge the tables and use an Anti-join. It's all done in the Merge dialog

[novicenew · Accepted solution]

Below is the script. Had to remove a 3rd column which is being created. 
let

Source1 = Table1,

Source2 = Table2,

DistinctTable1 = Table.Distinct(Table.SelectColumns(Source1, {"col1", "col2"})),

DistinctTable2 = Table.Distinct(Table.SelectColumns(Source2, {"col1", "col2"})),

Difference = Table.NestedJoin(DistinctTable1, {"col1"}, DistinctTable2, {"col1"}, "DistinctTable2", JoinKind.LeftAnti)

#"Removed Columns" = Table.RemoveColumns(Difference,{"DistinctTable2"}),

in

Difference

[HotChilli · Accepted solution]

Merge the tables and use an Anti-join. It's all done in the Merge dialog