If you can spare some some memory, you can pin a table into memory, so that the pages of this table remain in memory, once read into memory. This is only okay with smaller tables, but do not try this with larger tables as that can negatively impact SQL Server performance.
The following command can be used to pin a table in memory
( see DBCC PINTABLE )
EXEC sp_tableoption 'TableNameHere', 'pintable', 'true'
GO