I will Provide you a php script that will get list of first name, last name and keywords from you (it can be a csv file or you can enter manually using an interface) and then script will send invite to LinkedIn users for you while you can do other things, script will notify you via email when complete list will be processed.
I will give complete PHP source code to you, I can also upload and set it on your web server. If you don't have web server then I can host it on my server.
Please note that you will provide me username and password of your LinkedIn account, I need it for getting active session of that account for attaching it with script. If you don't want to share login info of your account then I can tell you that how you can get active session data of your account, it is easy.
Send bulk invites to LinkedIn users
I will provide you a script that will send bulk invites to LinkedIn users using your account.