We have a table, about 500Mb, that is updated and written every day. When machines updates, table is truncated and then re-populated with pg_bulk. But i think we strongly writes when importing new data tables..
so this is static data you update once per day from some external source? seems like a good candidate to put into RAM if you have enough. make sure your ram disk is not backed by swap, though.
how and how much do you query it? perhaps you don't even need indexes if it is on SSD or RAM disk.