Yes, you can combine them if they are from the same bank. Or you can enter them one at a time, even though they are all from the same bank. You can choose which you want to do.
To enter them one at a time, simply enter the first bank name and 1099-INT amount and complete the screens. When asked if you had interest from another bank, say YES and then enter the bank name again and the next 1099-INT amount, etc. When you are done entering all three, you will see the summary screen of all three listed and totalled. See sample screenshot attached.
