tablefunc extension?

Hi,
Yes, Amazon Aurora PostgreSQL 9.6 has the tablefunc extension available.
Note: if you want to check Aurora PostgreSQL 10, you can follow the steps below to check.

https://aws.amazon.com/rds/aurora/faqs/

The Amazon Aurora database engine is designed to be wire-compatible with PostgreSQL 9.6 and 10, and supports the same set of PostgreSQL extensions that are supported with RDS for PostgreSQL 9.6 and 10, making it easy to move applications between the two engines. 

For example, to find all of the extensions available for the PostgreSQL 9.6:

1. Services->RDS
2. Click on Parameter groups
3. Click on default.postgres9.6 (note: you might have to install this version one time (or v10) for this to show up in Param groups)
4. In the search field, type "tablefunc"
You will get: 
Name: rds.extensions
Values: address_standardizer,address_standardizer_data_us,bloom,btree_gin,btree_gist,chkpass,citext,cube,dblink,dict_int,dict_xsyn,earthdistance,fuzzystrmatch,hll,hstore,hstore_plperl,intagg,intarray,ip4r,isn,log_fdw,ltree,orafce,pgaudit,pgcrypto,pglogical,pgrouting,pgrowlocks,pgstattuple,pg_buffercache,pg_freespacemap,pg_hint_plan,pg_prewarm,pg_repack,pg_similarity,pg_stat_statements,pg_trgm,pg_visibility,plcoffee,plls,plperl,plpgsql,pltcl,plv8,postgis,postgis_tiger_geocoder,postgis_topology,postgres_fdw,prefix,sslinfo,tablefunc,test_parser,tsearch2,tsm_system_rows,tsm_system_time,unaccent,uuid-ossp

Hope this helps!
-randy