I ran this test to check.
DROP TABLE dbo.Numeric163_Low
GO
DROP TABLE dbo.Numeric163_High
GO
CREATE TABLE dbo.Numeric163_Low
(
    A numeric(18,2) NOT NULL,
    B numeric(18,2) NOT NULL,
    C numeric(18,2) NOT NULL,
    D numeric(18,2) NOT NULL,
    E numeric(18,2) NOT NULL,
    F numeric(18,2) NOT NULL,
    G numeric(18,2) NOT NULL,
    H numeric(18,2) NOT NULL,
    I numeric(18,2) NOT NULL,
    J numeric(18,2) NOT NULL,
    K numeric(18,2) NOT NULL,
    L numeric(18,2) NOT NULL,
    M numeric(18,2) NOT NULL,
)

CREATE TABLE dbo.Numeric163_High
(
    A numeric(18,2) NOT NULL,
    B numeric(18,2) NOT NULL,
    C numeric(18,2) NOT NULL,
    D numeric(18,2) NOT NULL,
    E numeric(18,2) NOT NULL,
    F numeric(18,2) NOT NULL,
    G numeric(18,2) NOT NULL,
    H numeric(18,2) NOT NULL,
    I numeric(18,2) NOT NULL,
    J numeric(18,2) NOT NULL,
    K numeric(18,2) NOT NULL,
    L numeric(18,2) NOT NULL,
    M numeric(18,2) NOT NULL,
)

INSERT INTO dbo.Numeric163_Low(A,B,C,D,E,F,G,H,I,J,K,L,M)
SELECT TOP (10000000)
   42949672.95,
     42949672.95,
   42949672.95,
   42949672.95,
   42949672.95,
   42949672.95,
   42949672.95,
   42949672.95,
   42949672.95,
   42949672.95,
   42949672.95,
   42949672.95,
   42949672.95
FROM tally a,tally b

INSERT INTO dbo.Numeric163_High(A,B,C,D,E,F,G,H,I,J,K,L,M)
SELECT TOP (10000000)
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96,
   42949672.96
FROM tally a,tally b
When I go into Reports\Standard\Disk Usage by Top Tables
I get this:

Which verifies your statement.