Is there any way to find if a dynamoDB table being used by any of my lambda functions? I have checked the code of "zip" type functions. But it is possible that the table may be in use by an "image" type function. There is no way to check that code.
In case of Lambda function I was told to change the concurrency to 0 in order to find if anything fails once the function is disabled. Is there any similar way to disable dynamoDB table?
If it's non production you could apply a resource based policy with a deny all statement. Your lambdas will begin to throw exceptions about lack of access.
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/access-control-resource-based.html
If it's production and you don't want to cause impact, then enabling cloudtrail dataplane logging will allow you to understand where requests are being made from.
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/logging-using-cloudtrail.html