Look at how much memory things other than SQL are currently taking.
Calculate (server memory) - (allocation for OS) - (what other things are using) = starting value for max server memory setting for SQL.
The wait stats you posted are probably not useful, as they're since SQL started. Anything more than a day and there's too much noise. Can you query syy.dm_os_wait_stats on an hourly interval (removing the unimportant waits), and calculate what the wait times are for busy hours of the day and post those?
And you're probably going to have to tune queries to get performance to a decent level. More memory is always good, but tuning queries and indexes gets the best gain.
With some very simple changes, I got a query that was running in 6.2 seconds to run in 12ms last week
With some very simple changes, I got a query that was running in 6.2 seconds to run in 12ms last week - Can you please put those tips here please if that is okay.
And i am collecting the data which is taking the querying the table, but currently, i have set that on friday and monday where there is too much of load on the server.