Try Repeat().
Two examples:
seq = {"1-B", "1-B", "1-B", "1-D", "1-D", "1-D", "1-F", "1-F", "1-F", "1-H", "1-H", "1-H", "1-J", "1-J", "1-J",
"1-L", "1-L", "1-L", "2-B", "2-B", "2-B", "2-D", "2-D", "2-D", "2-F", "2-F", "2-F", "2-H", "2-H", "2-H", "2-J",
"2-J", "2-J", "2-L", "2-L", "2-L"};
// Repeat sequence a predefined number of times
New Table( "example 2", New Column( "Part", Character, Values( Repeat( seq, 5 ) ) ) );
// Repeat sequence to fit an existing table
dt = New Table( "example", <<add rows( 400 ) );
dt << New Column( "Part",
Character,
Values(
Repeat( seq, Floor( N Rows( dt ) / N Items( seq ) ) ) || seq[1 :: Mod( N Rows( dt ), N Items( seq ) )]
)
);