One oracle user two tablespace issue
A tablespace is a logical entity in Oracle database which consists of physical data files stored on the underlying filesystem. 

We provide a quota of a certain size on the tablespace to a user. Which allows the user to create objects on it. And the user can explicitly defines on which tablespace he/she wants to create the object. 

Here is a simple example which represents(as far as I understand) your scenario. 

-- Create two tablespaces
SQL&gt; create tablespace meta_data datafile size 1m;

Tablespace created.

SQL&gt; create tablespace data datafile size 1m;

Tablespace created.

--Create a user and assign quota on one of the tablespaces 
--or you can define a tablespace a default tablespace 
--on which user can create an object by default.

SQL&gt; create user user1 identified by user1 quota unlimited on meta_data
  2  ;

User created.

--Assign quotas on another tablespace
SQL&gt; alter user user1 identified by user1 quota unlimited on data;

User altered.

--Now, the user can create objects on both of the tablespaces. 
--In order to make a connection, he or she needs to have 
--`create session` system privilege

SQL&gt; grant create session to user1;

Grant succeeded.

SQL&gt; conn user1@orclpdb
Enter password:
Connected.

--Let's create a table on meta_data tablespace.

SQL&gt; create table t1(col1 number) tablespace meta_data;
create table t1(col1 number) tablespace meta_data
*
ERROR at line 1:
ORA-01031: insufficient privileges

--Oops, lack of create table privilege

SQL&gt; conn sys@orclpdb as sysdba
Enter password:
Connected.
SQL&gt; grant create table to user1;

Grant succeeded.

SQL&gt; conn user1@orclpdb
Enter password:
Connected.
SQL&gt;  create table t1(col1 number) tablespace meta_data;

Table created.

SQL&gt; create table t2(col1 number) tablespace data;

Table created.