Sugeriría almacenar todo el polígono como un tipo de geometría. Si necesita "convertirlo" a geografía, use los métodos de geografía STNumPoints y STPointN para extraer los puntos individuales en secuencia y convertirlos según corresponda.
Hablando de la conversión, ¿en qué formato están sus datos ahora? No veo información de latitud/longitud allí, pero tal vez me esté perdiendo algo.
Editar:aquí hay una solución que acabo de codificar.
use tempdb;
create table tally (i int not null);
with
a as (select 1 as [i] union select 0),
b as (select 1 as [i] from a as [a1] cross join a as [a2]),
c as (select 1 as [i] from b as [a1] cross join b as [a2]),
d as (select 1 as [i] from c as [a1] cross join c as [a2]),
e as (select 1 as [i] from d as [a1] cross join d as [a2])
insert into tally
select row_number() over (order by i) from e
create unique clustered index [CI_Tally] on tally (i)
create table ace (g geometry)
insert into ace (g)
values (geometry::STGeomFromText(<<your polygon string here>>, 0));
select i, g.STPointN(t.i), g.STPointN(t.i).STAsText()
from ace as [a]
cross join tally as [t]
where t.i <= g.STNumPoints()
