It is a traffic calming hump (rounded top) wide and flat enough so that it can be used as a crossing, similarly to a traffic calming table (flat top). In countries such as the Netherlands, many traffic calming tables are intended or used as crossings. In other countries many crossings in general are not signed, or do not have a specific design.
Of course on through ways, higher speed ways, disconnected footway/calming combo it is less likely it is intended or used as crossing.
This area does not seem to have any kerb cuts (unmarked crossings), which makes me think they did not intend to add any actual crossings, but I will leave it as-is.

Added crossing footway in
https://www.openstreetmap.org/changeset/154296070

Sidenote: Some crossings, usually paths, sometimes leading around short barriers, are tagged informal=yes when they are clearly not intended as crossings.