Sql-server – How are these tempdb tables automatically created after each SQL Server restart

Following what @Damien_The_Unbeliever commented, yes those are Table variables only and if you are still observing them then it's evident that from whichever procedure those got created is still opened (or) not completed yet else those would have already been cleared from TempDB. To do a test try the code snippet and check against System Databases > tempdb > Temporary Tables: you will see that the table variable is exist.

declare @tab table(col1 int);
waitfor delay '8:10';
insert into @tab values(123);

Once you cancel the query, it gets cleared from TempDB.

on this question:

How to identify which query is filling up the tempdb transaction log?

you will be able to see a lot more, in different ways and with more technical information as why this is happen and what to do regarding it.

below is a script that I have to check what is filling up the tempDB. it may be a good starting point for your quest.

use tempdb

SELECT top 100
tsu.internal_objects_alloc_page_count,
tsu.user_objects_alloc_page_count,
es.host_name , 
es.login_name ,
es.program_name,
st.dbid as QueryExecContextDBID, 
DB_NAME(st.dbid) as QueryExecContextDBNAME, 
st.objectid as ModuleObjectId,

SUBSTRING(st.text, er.statement_start_offset/2 + 1,
          (CASE WHEN er.statement_end_offset = -1 THEN 
               LEN(CONVERT(nvarchar(max),st.text)) * 2 ELSE 
               er.statement_end_offset 
           END - er.statement_start_offset)/2) as Query_Text,

tsu.session_id ,
tsu.request_id, 
tsu.exec_context_id,

(tsu.user_objects_alloc_page_count 
  - tsu.user_objects_dealloc_page_count) as OutStanding_user_objects_page_counts,

(tsu.internal_objects_alloc_page_count 
 - tsu.internal_objects_dealloc_page_count) as OutStanding_internal_objects_page_counts,

er.start_time, 
er.command, 
er.open_transaction_count, 
er.percent_complete, 
er.estimated_completion_time, 
er.cpu_time, 
er.total_elapsed_time, 
er.reads,er.writes, 
er.logical_reads, 
er.granted_query_memory

FROM sys.dm_db_task_space_usage tsu 
inner join sys.dm_exec_requests er 
        ON (     tsu.session_id = er.session_id 
             and tsu.request_id = er.request_id) 

inner join sys.dm_exec_sessions es 
       ON ( tsu.session_id = es.session_id ) 

CROSS APPLY sys.dm_exec_sql_text(er.sql_handle) st

WHERE (tsu.internal_objects_alloc_page_count 
       + tsu.user_objects_alloc_page_count) > 0

ORDER BY (tsu.user_objects_alloc_page_count 
          - tsu.user_objects_dealloc_page_count)
        +(tsu.internal_objects_alloc_page_count 
           - tsu.internal_objects_dealloc_page_count) 

DESC