Definitely pond snail eggs. It is very unlikely you will be able to remove all of them because you probably can't see all of them but removing/destroying the eggs will keep them in check for now. If at any point you realize there is too many you could always just pick up assassin snails to keep them in check, and if you have a sand substrate or even small gravel the assassins will burrow in and wait for their prey, it's pretty interesting to watch.