Problem copying polygon data into a table

I have an text file in the format:

800|((180.87575,-45.98757),(180.87868, -45.98798),...,(Xn,Yn))

to be read into a table of:

attr type
id int
region polygon

using the command

copy <table> from '<file>' using delimiters '|';

The polygon has about 800 vertices (& is relatively small as some of the
polygons in my dataset go).

Trying to copy this into the table generates the error msg:

ERROR: Tuple is too big: size 12892

Does this mean that I've done summat incorrect, or that there is an
undocumented limit in what can be loaded in a "copy" command, or a limit
in the size (not area) of a polygon attribute?

The message gives me the impression that there is a limit in the length
of the string representing the polygon, so I could possibly fit more
vertices by reducing the precision of each, but it still implies a limit
which may render PostgreSQL unsuitable for my purposes.

Any advice appreciated....

Thanks,

Brent