What is the suffix of your email address is it gmail.com ? and make and model of tablet would be helpful
here are the instructions for setting up a gmail account. I would be tempted to let the tablet manage your imap/pop3 settings rather than get bogged down. Alternatively if you go to the store where you bought the tablet they may be able to help. However try these instructions first
Open the Settings menu and go to Accounts (& sync settings) on your device.
The Accounts settings screen displays your current sync settings and a list of your current accounts.
Touch Add account.
Touch Google to add your Google Apps account.
You will be prompted to Sign in to your Google Account.
Enter your full Google Apps email address as your username, and then enter your password.
Select which services you’d like to sync. choose mail/contacts/calendar etc
Once done simply open the gmail app it looks like an envelope with an "M" over it to get your mail
http://gappstips.com/android/android-gmail-setup-instructions/
The wifi doesn't distort the password, they are case sensitive and also check for spaces at the end which shouldn't be there
***Update ***
Ok for galaxy S7 here are more specific instruction, choose automatic rather than manual setup when given a choice to skip the pop3/imap stuff
How to set up email account on the Galaxy S7
.
To get started, tap Apps from the Home screen.
Tap Email.
Note: If you can’t find the Email app shortcut from the Apps screen, open the Samsung folder. On some GS7 variants, the Email app is located in the Samsung folder.
On the next screen, tap Add New Account.
Note: If there is already an account registered on your phone, just tap an email address in the above-given list.
Type in your email address and password.
tap SIGN IN if you want your phone to complete the setup process by automatically searching for your email server settings, don't choose the manual option.
Wait for your device to verify if the server settings you enter are all correct. If your device successfully connects to the server using the settings you entered, you will be prompted with the Sync schedule screen.
Configure sync options according to your preference.
Tap SIGN IN.
Enter a name for the account. If you want to create a signature to all your outgoing messages, you can enter your name or any signature you want to indicate on the appropriate field.
Tap DONE to complete the process. After that, you should see email messages populating your inbox