To be clear, there's no way to show the Character Sheet tab directly. You can, as Mike mentions, create macros to show the contents of the character sheet in chat, but that can be a pain if your system is complex and has a lot of stats, skills, etc. One thing you can do is copy each players sheet, set the copy to editable by all, and then players can look at copies without having to worry about people changing stats. Of course, they wont be up to date if characters change frequently. If you trust your players npt mess things up (either deliberately or accidentally), you can just give them edit rights over all the PCs. I wouldnt do this myself, purely because of the easy of making accidental changes and not noticing for a while. I've done this as GM viewing a pc sheet and thinking I was viewing a different sheet, accidents happen. But it is one way to do it.