Table.selectrows with list.contains loading issue

I’ve filter values in Table1 and creating a reference table. I then converted this table to a key ID list.  And apply as filter to table2 using Table.selectrows( pervious step, each list.contains(list.buffer(list.distinct (mykeylist)),[table2keycolumn])). However, the loading process is taking  forever , and I’m getting a timeout message. my list contains approximately 400,000 rows, while Table2 has around 6 million rows that I want to reduce to my list, Can you help me troubleshoot this issue or point me in the right direction