The “focused tiddler” problem makes this challenging in “vanilla” TW… but luckily, there are several plugins designed to tackle this issue. Here’s one by @Scribs: Nav - keyboard navigation plugin 🧭
And another linked in the same thread: Demo of tw5-keyboard-navigation — Navigate through your TiddlyWiki using only your keyboard
I think I’ve seen at least one other implementation, possibly back in the days of the old Google Group, but I don’t have the link on hand. You may have luck searching for “tiddlywiki keyboard navigation” in your search engine of choice.
I haven’t tested @Scribs’s version personally, but of the two above it’d be my general recommendation, as tw5-keyboard-navigation uses unmarked e (and so on) for its keybindings. I suspect this would be very quickly frustrating if you use your keyboard for anything else in view mode — say, an $edit-text widget.